The provision, as now amended, stood as follows: "(1) Any dealer or other person aggrieved by an order made by the assessing authority, other than an order mentioned in section 10 A may, within thirty days from the date of serv ice of the copy of the order, appeal to such authority as may be prescribed: Provided that no appeal against an assessment order under this Act shall be entertained unless the appel lant has furnished satisfactory proof of the payment of not less than (a) Where all the returns for the assessment year have been filed, the amount of tax or fee due under this Act on the turnover of sales or purchases, as the case may be, admitted by the appellant in the returns filed by him or at any stage in any proceeding under this Act, whichever is greater; or (b) Where some the returns for the assessment year have not been filed or no return has been filed for such year, the amount of tax or fee due under this Act on the turnover of sales or purchases, as the case may be, admitted by the appellant in the returns, if any, filed by him or at any stage in any proceedings under this Act or 20 per cent of the amount of tax or fee assessed whichever is greater; and Provided further that the appellate authority may, for special and the adequate reasons to be recorded in writing,.