With respect to a credit card which may be used for extensions of credit in sales transactions in which the seller is a person other than the card issuer, the card issuer may not, by contract or otherwise, prohibit any such seller from offering a discount to a cardholder to induce the cardholder to pay by cash, check or similar means rather than use a credit card.
Okla. Stat. tit. 14A, § 1-110