I
The Millers claim that Wikel Mfg. and its president, David Wikel, began breaching the distributorship contract in 1982 by making direct sales to the Millers’ customers in Michigan; imposing price schedules on the Millers; and, ultimately, by wrongfully terminating the Millers’ distributorship contract. The jury specifically found that Wikel Mfg. had breached its contract with the Millers and that the Millers had suffered $1.5 million in damages as a result. The trial court entered judgment for plaintiffs on that count and in that amount. The court of appeals reversed this judgment on two grounds: first, that the Millers had waived their right to complain about Wikel Mfg.’s direct sales by continuing their relationship with Wikel Mfg. with knowledge of such direct sales; and second, that the agreement under which the parties operated was terminable at will by either party.
It was proven at trial that the Millers had been aware of direct sales by Wikel Mfg. in Michigan since 1971 and that the Millers had accepted com*78missions on these sales. Such sales were in contravention of the exclusive distributorship contract. The court of appeals reasoned that the Millers’ election to continue as Wikel Mfg.’s distributor, notwithstanding Wikel Mfg.’s actions, constituted a waiver of their rights under the agreement, and thus that they were estopped from asserting a breach-of-contract claim on this basis.
Waiver and estoppel are affirmative defenses under Civ. R. 8(C), and thus must be affirmatively set forth. The record shows that the defendants never asserted waiver or estoppel in their answer, nor did they raise these defenses in any manner during the proceedings. It is axiomatic that “[i]ssues not raised in the lower court and not there tried and which are completely inconsistent with and contrary to the theory upon which appellants proceeded below cannot be raised for the first time on review.” Republic Steel Corp. v. Bd. of Revision of Cuyahoga Cty. (1963), 175 Ohio St. 179, 23 O.O. 2d 462, 192 N.E. 2d 47, syllabus. Therefore, we hold that it was error for the court of appeals to have sua sponte raised waiver and estoppel on the defendants’ behalf and to have reversed the judgment in plaintiffs’ favor on that basis.
The second ground on which reversal of this count rested was the finding by the appellate court that the parties had modified their contract and that the new arrangement was terminable at the will of either party. We agree that a distributorship agreement with no express provision as to duration is generally terminable at will by either party after a reasonable duration and on reasonable notice. See, e.g., Excello Wine Co. v. Monsieur Henri Wines, Ltd. (S.D. Ohio 1979), 474 F. Supp. 203, 208 (applying Ohio law).
At trial the jury was given two instructions pertinent to the issue of the contract’s duration. It was first charged:
“There has been no evidence of a definite termination date of the original contract. I instruct you that when a continuing contract such as this has no specific terminal date it may be terminated by either party after a reasonable time and after reasonable notice of intention to terminate.”
The jury was subsequently charged:
“If you find that the distributorship agreement has no expressed term as to its duration it is terminable without cause after a reasonable period of existence and upon reasonable notice.” (Emphasis added.)
The first jury charge stated that there had been no evidence of a specific termination date of the distributorship contract. The proper rule of law was given regarding an oral contract with no specific termination date, i.e., that such contracts are generally terminable by either party upon reasonable notice. However, while the agreement between Wikel Mfg. and the Millers had no specific termination date, the agreement’s duration and the parties’ rights of termination were apparently provided for. The testimony of both the Millers and of an officer of Wikel Mfg. revealed that the agreement was to continue as long as Wikel Mfg. remained in the business of manufacturing the products and equipment, and the Millers stated that they alone had the right to terminate the arrangement. Since the record reflects some dispute on this matter, the second jury charge left to the jury the factual issues of whether this contract had an expressed duration and, as a result, whether it was terminable at the will of either party. The jury presumably found that the contract was not mutually terminable, as the jury’s *79answers to interrogatories reflect a finding that Wikel Mfg. had indeed breached the contract. Wikel Mfg. made no objection to the second charge that left these issues to the jury. Having failed to object to this instruction, Wikel Mfg. waived its right to appeal the court’s submission of these issues to the jury. Thus, the court of appeals erred in finding that the contract was terminable at the will of Wikel Mfg.
Since we reject both grounds on which the court of appeals reversed the judgment for plaintiffs on their breach-of-contract claim, we must conclude that such judgment was proper. We are not inclined to set aside the jury’s finding with respect to liability or damages. Accordingly, the jury’s award to the Millers for Wikel Mfg.’s breach of contract must be reinstated.
II
The Millers also asserted a claim against David Wikel individually for tortious interference with contract. Throughout the business relationship between the Millers and Wikel Mfg., David Wikel was the president and majority stockholder of Wikel Mfg. Therefore, it would appear that any activities he was involved in were on behalf of Wikel Mfg. and could not be assessed as individual in nature. Personal liability of Wikel could result only where his actions benefited him solely in a personal capacity.
The only instance that suggests that David Wikel acted solely to benefit himself centered on the sale of a Florida business which he personally owned. The buyer of Wikel’s Florida business was one A. Michael Ford. As it happened, Ford’s other business activities included the purchase of Wikel Mfg. products from the Millers in Michigan. Plaintiffs argue that Wikel, pursuant to the sale of his Florida business to Ford, agreed that he, Wikel, would require that the Millers lower their prices on the products they sold Ford. At trial, however, this assertion was specifically denied by Ford, who testified that the Millers’ lowering of their prices in Michigan was not part of the purchase agreement between himself and David Wikel.
The record is devoid of any other evidence supporting personal liability of David Wikel. Thus, there is no basis for the jury’s finding against Wikel on this claim. Accordingly, the appellate court’s decision reversing Wikel’s individual liability is affirmed.
Ill
In their fourth proposition of law appellants argue that the trial court erred in denying their motion for prejudgment interest pursuant to R.C. 1343.03.
R.C. 1343.03 provides in pertinent part:
“(A) In cases other than those provided for in sections 1343.01 and 1343.02 of the Revised Code, when money becomes due and payable upon any bond, bill, note, or other instrument of writing, upon any book account, upon any settlement between parties, upon all verbal contracts entered into, and upon all judgments, decrees, and orders of any judicial tribunal for the payment of money arising out of tortious conduct or a contract or other transaction, the creditor is entitled to interest at the rate of ten per cent per annum, and no more, unless a written contract provides a different rate of interest in relation to the money that becomes due and payable, in which case the creditor is entitled to interest at the rate provided in that contract.
* *
“(C) Interest on a judgment, decree, or order for the payment of *80money rendered in a civil action based on tortious conduct and not settled by agreement of the parties, shall be computed from the date the cause of action accrued to the date on which the money is paid, if, upon motion of any party to the action, the court determines at a hearing held subsequent to the verdict or decision in the action that the party required to pay the money failed to make a good faith effort to settle the case and that the party to whom the money is to be paid did not fail to make a good faith effort to settle the case.”
Appellants initially sought prejudgment interest under both R.C. 1343.03(A) and (C),1 but before this court they have limited their argument to their right to interest from Wikel Mfg. on their breach-of-contract claim. We find this argument to be without merit.
Prejudgment interest under R.C. 1343.03(A) is awarded from the time the amount at issue becomes “due and payable.” Appellants argue that damages for breach of contract are due and payable when they are “ascertainable by computation or by reasonably certain calculations with reference to existing market values and recognized valuation methods.” The trial court essentially rejected the argument that the damages were reasonably ascertainable in this case, and we find nothing in the record to cause us to disturb this holding. Accordingly, we affirm the denial of prejudgment interest.
Judgment reversed in part and affirmed in part.
Moyer, C.J., Wright, H. Brown and Evans, JJ., concur. Sweeney, Holmes and Douglas, JJ., separately concur in part and dissent in part. John R. Evans, J., of the Third Appellate District, sitting for Res-NICK, J.In their original motion appellants relied on R.C. 1343.03(C) and asserted that they “offered to settle for four hundred thousand dollars ($400,000.00) and the defendants refused to consider any settlement amount.” Appellees responded by arguing that R.C. 1343.03(C) provides for interest on judgments arising from “tortious conduct,” and thus that this provision is inapplicable because “the instant action is one based on contract * * Appellants subsequently modified their request, seeking prejudgment interest under R.C. 1343.03(C) only against David Wikel individually, on their tortious-interferencewith-contract claim against him, and interest under R.C. 1343.03(A) against Wikel Mfg., on their breach-of-contract claim. Following a hearing the trial court overruled appellants’ motion. On appeal appellants continued to seek prejudgment interest from both Wikel Mfg. and David Wikel, under R.C. 1343.03(A) and (C), respectively. The court of appeals held that these arguments were “rendered moot” by its reversal of the judgment in favor of appellants. The quest for prejudgment interest from David Wikel individually under R.C. 1343.03(C) appears to have been abandoned by appellants, as their brief filed with this court addresses only their right to interest from Wikel Mfg. under R.C. 1343.03 (A). Accordingly, we express no opinion on their right to interest on their judgment against Wikel individually. However, since we have affirmed the reversal of this judgment in Part II, supra, the question of interest on that judgment would be moot in any event.