(1) Notwithstanding the provisions of any contract to the contrary, any buyer may prepay in full at any time before maturity the obligation of any contract.

(2) If such obligation is prepaid in full by cash, a new loan, or otherwise after the first installment due date, the borrower shall receive a rebate of an amount which shall be not less than the amount obtained by applying to the unpaid principal balances as originally scheduled or, if deferred, as deferred, for the period following prepayment, according to the actuarial method, the rate of the time-price differential previously stated to the borrower. The licensee may round the rate of the time-price differential to the nearest one-half of one percent if such procedure is not consistently used to obtain a greater yield than would otherwise be permitted. Any default and deferment charges which are due and unpaid may be deducted from any rebate. No rebate shall be required for any partial prepayment. No rebate of less than one dollar need be made. Acceleration of the maturity of the contract shall not in itself require a rebate. If judgment is obtained before the final installment date, the contract balance shall be reduced by the rebate which would be required for prepayment in full as of the date judgment is obtained.