A high risk home loan may not contain terms under which a consumer must pay a prepayment penalty for paying all or part of the principal before the date on which the principal is due. For purposes of this Section, any method of computing a refund of unearned scheduled interest is a prepayment penalty if it is less favorable to the consumer than the actuarial method as that term is defined by Section 933(d) of the federal Housing and Community Development Act of 1992, 15 U.S.C. § 1615(d).