Section 51-13-05 - Prepayment of retail installment contract1. At any time before maturity, a buyer may pay in full the remaining principal due on a retail installment contract and is entitled to a refund of finance charges as follows: a. The refund must be at least the finance charge paid in excess of that computed under the simple interest method, using the annual percentage rate disclosed under federal law to the nearest one-fourth of one percent.b. For a retail installment contract in which the amount financed is not more than ten thousand dollars, an acquisition cost of at most fifteen dollars may be deducted from the refund.c. For all retail installment contracts, a refund is not required if it is less than one dollar.2. Notwithstanding section 51-13-06.2, this section applies to retail installment contracts for agricultural purposes and to retail installment contracts for more than twenty-five thousand dollars.