Waiver of lender's noncompliance. The Secretary may waive a lender's noncompliance with any provision of this part, subject to statutory limitations, when it is determined that enforcement of the regulations would impose an injustice upon a lender which has substantially complied with the regulations in good faith and refunded or credited any excess charge made, and when such waiver does not involve an increase in the Secretary's obligation beyond that which would have been involved if the lender was in full compliance with the regulations.