Section 19. Refund

The prescribed authority shall refund to a person the amount of tax, penalty, interest and fees, if any, paid by such person in excess of the amount due from him, and the refund may be made either by cash payment or, at the option of the person, by deduction of such excess from the amount of tax penalty, interest and fee due in respect of any other period : Provided that, the prescribed authority shall first apply such excess towards the recovery of any amount due in respect of which a notice under section 9 has been served, and shall then refund the balance, if any.