Refund of tax.

Subject to the provisions of this Act and the rules made thereunder, the Commissioner shall, in such manner and within such period, as may be prescribed, refund to the proprietor the amount of tax, penalty or interest, if any, paid by such proprietor in excess of the amount due from him. The refund may either be made by refund voucher or at the option of the proprietor, by refund adjustment order: Provided that the Commissioner shall first apply such excess amount towards the recovery of any amount due, in respect of which, a notice of demand under sub-section (1) of section 14 has been served or towards any other amount, which is due, but not paid, and shall refund the balance amount, if any.