(1) If a claim has been contested at the verification meeting or if the amount of the remaining claim held by a creditor entitled to separate satisfaction has not yet been determined, default on performing the insolvency plan for the purpose of section 255 (1) is not to be assumed if, up until final determination of its amount, the debtor takes account of the claim in the amount which corresponds to the decision by the insolvency court on the voting right of such creditor upon the vote on the plan. If the court has not decided on the voting right, then at the request of the debtor or of the creditor it is to subsequently determine the extent to which the debtor has to provisionally take such claim into account.
(2) If such final determination shows the debtor falling short in payments, that debtor is required to pay the arrears. Default to a considerable extent in performance of the plan is to be assumed only if the debtor fails to pay the arrears although reminded by the creditor in writing with a grace period of no less than two weeks.
(3) If such final determination shows the debtor has overpaid, then the debtor may claim restitution of the overpaid amount only to the extent that it also exceeds the immature part of the creditor’s claim under the insolvency plan.