The mortgagee shall cancel any hazard insurance policy as of the date of the filing for record of the deed to the Commissioner subject to the following conditions:

(a) The amount of the return premium due the mortgagee because of such cancellation may be calculated on a “short-rate” basis and reported on fiscal data supporting the application for debentures and the amount shall be deducted from the total amount claimed.

(b) If the mortgagee's calculation of the return premium is less than the actual return, the amount of the difference between the actual refund and the calculated amount shall be remitted to the Commissioner, accompanied by the carrier's or agent's statement.

(c) If the mortgagee's calculation of the return premium is more than the actual return, the mortgagee may file with the Commissioner a claim, supported by the carrier's or agent's statement of the amount of the refund, whereupon the Commissioner shall issue a check to the mortgagee in settlement of the claim.