(a) Notwithstanding the provisions of § 12-601(k) of this subtitle, for the purposes of this section, “goods” means any personal property bought for use primarily for personal, family, or household purposes regardless of the cash price of the goods.

(b) A buyer may prepay at any time, without penalty, all or part of the outstanding balance payable under an installment sale agreement relating to consumer goods.

(c) (1) Except as provided in subsection (d) of this section, if the buyer pays the balance in full before maturity, the holder immediately shall refund to him a portion of the finance charge, including the charge provided for in § 12-610(2) of this subtitle.

(2) The amount of the refund shall be calculated according to the actuarial method based on the original schedule of payments.

(d) If a prepayment is made, the holder is entitled to retain a finance charge of at least $6.

(e) If the amount of the credit prepayment is less than $1, no refund need be made.