(a) At the time a seller accepts the credit of the buyer and establishes a retail installment account for that buyer's use, the seller shall confirm this fact to the buyer in writing. Such confirmation shall contain a clear and understandable statement of the rates of service charge, without regard to the variations contained in § 4337 of this title, which will be collected from the buyer, but may contain the clause that such rates are subject to change if permitted by law. This confirmation shall also contain a legend that the buyer may at any time pay the entire balance.
(b) The confirmation shall be in type no smaller than elite typewriter characters.
(c) If no copy of the confirmation is retained by the seller, a notation in the permanent record showing that such confirmation was mailed, and the date of mailing, shall serve as prima facie evidence of such mailing.