With respect to consumer credit transactions, where the debt is payable in installments, not made pursuant to an open-end credit plan and in which the original amount financed is one thousand dollars ($1,000) or less, the debt shall be scheduled to be payable in substantially equal installments at equal periodic intervals, except to the extent that the schedule of payments is adjusted to the seasonal or irregular income of the debtor or when the transaction is a single principal payment obligation irrespective of the scheduled interest payments, and:
Ala. Code § 5-19-18 (1975)