(15)If the Commissioner is of the opinion that any goods, not being a spirituous beverage, manufactured from spirits under rebate of excise duty in terms of a formula approved by him under any item of Schedule No. 6 are used as a beverage he may forthwith revoke his approval of such formula. (16)No refund or drawback of duty shall be paid by the Commissioner under this section unless an application therefor, duly completed and supported by the necessary documents and other evidence to prove that such refund or drawback is due under this section, is received by the department in — (a) the case of goods exported, where the goods were exported — (i) by post within a period of six months from the date on which such goods were posted; (ii) in any other manner within a period of six months from the date of entry of such goods for export; and (b) (i) in respect of any refund referred to in subsection (1)(f), within a period of six months from the last date of any period of use of any distillate fuel to which the application for such refund relates: Provided that no refund shall be paid if the quantity of distillate fuel to which the application for such refund relates is less than such refund relates is less than such quantity as may be prescribed; and (ii) in all other cases, within a period of six months from the date on which such refund first becomes due. (Amended A.2/1985; A.5/1991.) (16bis) (a) Subject to the concurrence of the Minister, the Minister for Commerce, Industry and Tourism may at any time after a permit by virtue of which goods may, in terms of any item of Schedule 3,4 or 6, be entered under rebate of duty has been refused, but not later than two years after duty was paid on those goods, issue a permit authorising entry of those goods under rebate of duty in accordance with the provisions of the item concerned if, with due regard to any facts which became known after such a permit has been refused, he is satisfied that he would have issued such a permit if those facts were then known. (b) For the purposes of subsections 39(3), 39(4) and 39(5) — (i) any bill of entry passed in relation to goods in respect of which a permit is issued under paragraph (a) shall be deemed to have been passed in error by reason of duty having been paid on goods intended for purposes or use under rebate of duty under this section; (ii) the .goods in respect of which such a permit is issued shall be deemed to have qualified at the time duty was paid on such goods in all respects for rebate; and