Except as provided in subsection (b) of this section, if a holder violates any provision of this subtitle, no holder may collect or receive any finance charge from the buyer. If the seller or any subsequent holder unintentionally and in good faith fails to comply with any provision of §§ 12-504 through 12-507 of this subtitle, the holder may correct the error within 10 days after: He notices it; or The buyer notifies him in writing of the error. If the holder corrects the error within the 10-day period, he may not be subject to any penalty under this subtitle.