4. Notwithstanding anything contained in any law for the time being in force or in any contract, decree or other instrument having force by virtue of any such law and save as otherwise expressly provided in this Act —
(a) every debt, together with any interest, payable on the date of commencement of this Act, by a debtor whose annual household income does not exceed two thousand and four hundred rupees, shall with effect from the date of such commencement, be deemed to be wholly discharged ;
[(b) every debt payable on the date of such commencement by a debtor whose annual household income exceeds two thousand and four hundred rupees shall be wholly discharged, if the debtor—
(i) has paid, in the discharge of his debt, a sum exceeding or equivalent to double the amount of principal in respect of the debt, at any time before such commencement, and such discharge shall be effective from the date of such commencement ;
(ii) pays after the date of such commencement, a sum which, together with any sum already paid in the discharge of such debt, is equivalent to or exceeds double the amount of principal in respect of the debt, or the amount actually due whichever is less, and such discharge shall be effective from the date of such payment. ]
Explanation— Nothing in this section shall be construed to entitle any debtor to the refund of any part of a debt already repaid by him or recovered from him before the commencement of this Act.