Any person aggrieved by an order made by the State Commission in exercise of its powers conferred by sub-clause (i) of clause (a) of section 17 may prefer an appeal against such order to the National Commission within a period of thirty days from the date of the order in such form and manner as may be prescribed:
     Provided that the National Commission may entertain an appeal after the expiry of the said period of thirty days if it is satisfied that there was sufficient cause for not filing it within that period:
     ¹[Provided further that no appeal by a person, who is required to pay any amount in terms of an order of the State Commission, shall be entertained by the National Commission unless the appellant has deposited in the prescribed manner fifty per cent. of the amount or rupees thirty-five thousand, whichever is less].