To cover the cost of processing a credit or charge card transaction, and pursuant to section 5–2–212, Colorado Revised Statutes, a seller or lessor may impose a processing surcharge in an amount not to exceed the merchant discount fee that the seller or lessor incurs in processing the sales or lease transaction. A seller or lessor shall not impose a processing surcharge on payments made by use of cash, a check, or a debit card or redemption of a gift card.