All claims payable in the form of indemnities under the terms of a service plan contract shall be paid within 30 days following receipt by the corporation of due proof of loss. Failure to pay within such period shall entitle the subscriber to interest at the rate of 9 per cent per annum from the 30th day after receipt of such proof of loss to the date of late payment, provided that interest amounting to less than one dollar need not be paid.
     The requirements of this section shall apply to any service plan contract delivered, issued for delivery, renewed or amended on or after 180 days following the effective date of this amendatory Act of 1985.