decreed that the words of discharge of the mortgage were written upon the margin of the record book in the registry of deeds by accident and mistake, and did not prove an actual payment of the mortgage debt, or cancel or discharge the mortgage, but were inoperative and void, and left it in the same force and effect as before; and that the defendant and all persons claiming by, through or under her should be prohibited and enjoined from setting up, using or relying upon said words of discharge, either as proof of payment of the debt, or a discharge of the mortgage; with liberty to either party to apply to the court hereafter.