In the case of a precomputed consumer credit transaction which is unpaid at contractual maturity, the rate of the loan finance charge or the credit service charge for the period beginning as of contractual maturity until payment in full may not exceed the rate of the loan finance charge or the credit service charge previously agreed to by the extender of credit and the debtor at the time the consumer credit transaction was entered into. Provided however, beginning one year after contractual maturity, the rate shall not exceed 18% per annum.
La. R.S. § 9:3522