The Food Inspector shall certify for refund purposes, any overpayment of license and fees, produced by any application for license under an incorrect class. If an incorrect class license is replaced by a new license of proper class, credit may be taken for the payments of the cancelled incorrect license fee against the fee(s) due for the corrected license. The incorrect license certificate must be surrendered to receive credit except in the instance of a multiple class license certificate, in which case the Food Inspector shall cancel out and initial the incorrect class and certify the credit or refund without surrender of the corrected license certificate.