Recovery of certain amounts not duly payable. 76bis. (1) If the Commissioner, acting under the provisions of section 75 or 76, pays to any person by way of a refund or drawback any amount which was not duly payable to that person under those provisions or which was in excess of the amount due to that person by way of a refund or drawback under those provisions, that amount or the excess, as the case may be, shall be repaid by the person concerned to the Commissioner upon demand, failing which it shall be recoverable in terms of this Act as if it were the duty or charge concerned or part of such duty or charge, as the case may be. (2) Subsection (1) shall apply mutatis mutandis to any amount set off in terms of section 77(1). (Added A.5/1991.) Over-payment in respect of excisable goods and sales duty goods. 77. (1) Any amount due to a licensee of a duty warehouse who, in terms of the regulations, is permitted to pay excise duty or sales duty monthly or quarterly, in respect of such duty paid by him for which he was not liable or any provisional refund granted by him in terms of section 75(1bis) or which is refundable to him in terms of item 534.00 of Schedule No. 5 or any item of Schedule 6 or 7 may, at any time within a period of two years from the date on which such amount first becomes due, be set off against any amount for which such licensee subsequently becomes liable in respect of excise duty or sales duty: Provided the accounts or bills of entry submitted by such licensee in respect of the payment of any amount against which any amount so due to him has been set off are accompanied by a full statement by such licensee, supported by a certificate by an officer, giving full particulars of the excise duty or sales duty so paid and a full account of the circumstances under which the payment thereof took place and by such documentary evidence as the Commissioner may in each case require. (Amended A.2/1985; A.5/1991.) (2) If the set-off of any amount is not allowed by the Commissioner in terms of subsection (1) such amount shall be re-debited to the account of such licensee. (3) With the permission of the Commissioner and subject to such conditions as he may impose, any amount of sales duty or excise duty specified in Section B of Part 2 of Schedule No. 1 paid by the licensee of a duty warehouse licensed in terms of this Act in respect of sales duty goods or excisable goods specified in Section B of Part 2 of Schedule No. 1 sold by him to any person whose premises are not so licensed and who has exported such goods or supplied them to any other person entitled to acquire such goods under rebate of sales duty or excise duty specified in Section B of Part 2 of Schedule No. 1, may be set off against any amount for which such licensee subsequently becomes liable in respect of sales duty or excise duty specified in Section B of Part 2 of Schedule No. 1: