On an amount owed for a credit card transaction under a lender credit card agreement that imposes or allows the creditor to receive a merchant discount, the creditor may not contract for, charge, or receive:
(1) a rate that exceeds the ceiling provided under Section 303.006(c); or
(2) a fee or charge that:
(A) is not allowed under Chapter 346; or
(B) exceeds the amount allowed under Chapter 346.