The holder of a contract, upon request by the buyer, may extend the scheduled due date of all or any part of any installment or installments or deferred payment or payments or renew or restate the unpaid time balance of such contract, the amount of the installments, and the time schedule therefor and may collect for such extension, deferment, renewal, or restatement a refinance charge computed as follows: In the event the unpaid time balance of the contract is extended, deferred, renewed, or restated, the holder may compute the refinance charge on such amount by adding to the unpaid time balance the cost for insurance and other benefits incidental to the refinancing plus any accrued delinquency and collection charges after deducting any refund which may be due the buyer at the time of the renewal or restatement by prepayment pursuant to Code Section 10-1-34, at the rate of the finance charge specified in subsection (a) of Code Section 10-1-33, and by reclassifying the motor vehicle by its then year model, for the term of the refinancing agreement, but otherwise subject to the provisions of this article governing computation of the original finance charge. The provisions of this article relating to minimum finance charges under subsection (b) of Code Section 10-1-33 and acquisition costs under the refund schedule in Code Section 10-1-34 shall not apply in calculating refinance charges on the contract extended, deferred, renewed, or restated. If all unpaid installments are deferred for not more than two months, the holder may, at his election, charge and collect for such deferment an amount equal to the difference between the refund required for prepayment in full under Code Section 10-1-34 as of the scheduled due date of the first deferred installment and the refund required for prepayment in full as of one month prior to said date times the number of months in which no scheduled payment is made.