With respect to a consumer credit sale or consumer loan, refinancing or consolidation, the seller or lender may by agreement with the consumer refinance the unpaid balance owed to such seller or lender and may contract for and receive the applicable sales finance charge or loan finance charge, as the case may be, based on the amount financed of a sale or principal of a loan resulting from the refinancing at a rate not exceeding that permitted by the provisions on sales finance charge for consumer credit sales or loan finance charge for consumer loans, as the case may be. For the purpose of determining the sales finance charge or loan finance charge permitted, the amount financed or principal resulting from the refinancing comprises the following:
(1) If the transaction was not precomputed, the total of the unpaid balance and the accrued charges on the date of refinancing or, if the transaction was precomputed, the amount which the consumer would have been required to pay upon refinancing pursuant to the provisions on rebate upon refinancing on the date of refinancing except that for the purpose of computing this amount no minimum sales finance charge or minimum loan finance charge shall be allowed;
(2) Appropriate additional charges, payment of which is deferred; and
(3) Accumulated unpaid delinquency or deferral charges.