(a)Where a return has been made under section 13 or section 14 or in response to a notice under clause (i) of sub-section (4),--(i)if any tax or interest is found due on the basis of such return after adjustment of any amount paid by way of tax or interest, an intimation shall be sent to the assessee specifying the sum so payable and such intimation shall be deemed to be a notice issued under section 31 and all the provisions of this Act shall apply accordingly; and(ii)if any refund is due on the basis of such return, it shall be granted to the assessee;