Regulation of finance charges

It shall be unlawful, directly or indirectly, to charge, contract for, collect, or receive any finance charge, on a credit sale contract except as is provided by this section. (1) If the finance charge is stated as a dollar amount and is added on or deducted in advance, and the buyer promises to pay a fixed total of payments, the finance charge shall not exceed the amount of interest or discount which could lawfully be added on or deducted in advance by a financial services loan company under article 9 of chapter 412 on a loan to run for the same period as the credit sale contract, where the actual cash received by the borrower would be equal in amount to the principal balance of the credit sale contract, provided that a minimum finance charge of not more than $10 shall be allowable in a credit sale when the finance charge is stated in a dollar amount. Upon maturity of a contract, the rate of finance charge on the unpaid principal balance of the contract shall be eighteen per cent a year, unless a lesser rate for after maturity finance charge is specified in the contract. (2) As an alternative to the finance charge authorized by paragraph (1), a seller may contract for and receive a finance charge at a rate not exceeding twenty-four per cent a year on the principal balance remaining unpaid from time to time under the contract, whether or not the rate of the finance charge under the contract is fixed or variable. Upon maturity of a contract, the rate of finance charge on the unpaid principal balance of the contract may be twelve per cent a year, the original contract rate of finance charge or, in the case of any extension or deferral, the rate of finance charge permitted by this chapter on the amount extended or deferred, whichever is greatest.