The special privilege tax imposed by § 67-3-203 shall be refundable to the user of such petroleum products as are shown to be used directly in fabricating or processing tangible personal property for resale. There is expressly excluded from this section any use for the purpose of space heating, illumination, or the operation of internal combustion engines. The refund may be claimed on a monthly basis before the expiration of thirty (30) days following the month for which such refund is to be made.