Upon termination of insurance prior to maturity, and in accordance with the refund formulas prescribed herein, and in accordance with the insurer's established refund procedures, each insured debtor shall receive from the insurer any refund of unearned identifiable insurance charge either in cash, by check, or by credit to and against the insured debtor's indebtedness (provided that such credit shall be applied only to the indebtedness to which the insurance charges are attributable). Insurers shall be responsible for the establishment of procedures by which refunds or credits are to be made, and shall furnish to the creditors schedules or methods for the calculation of refunds or credits to be made in the event of termination of insurance. Insurers shall also furnish instructions to creditors with respect to the duties in making of such refunds or credits.