Haw. Rev. Stat. § 476-23
Notwithstanding any provisions of a credit sale contract to the contrary, a buyer, upon five days' prior notice to the holder, may satisfy in full at any time before maturity the debt of the contract and in so satisfying the debt shall receive a refund credit thereon for such anticipation of payments, if the finance charge has been paid in advance. The amount of the refund shall represent at least as great a proportion of the total finance charge, less an acquisition cost of $10, as the sum of the periodical time balances, after the day of prepayment, bears to the sum of all the periodical time balances under the schedule of payments in the contract. When the amount of the credit for anticipation of payments is less than $1, no refund need be made.
HRS § 476-23