(a) The holder of a retail installment contract, upon request by the buyer, may agree to an amendment thereto to extend the scheduled due date of all or any part of any installment or installments or to renew, restate, or reschedule the unpaid balance of the contract.

(b) The amendment to the contract must be confirmed in writing signed by the buyer and the holder. The writing shall set forth the terms of the amendment, and shall either be delivered or mailed to the buyer at the address as shown on the contract. The writing together with the original contract and any previous amendments thereto shall constitute the retail installment contract. (Added 1961, No. 227, § 8, eff. Jan. 1, 1962; amended 1989, No. 122, § 9, eff. June 30, 1989.)