All arrears of dues payable to a Government electrical undertaking and outstanding against a debtor at the commencement of this Act shall also be recoverable in the manner provided for in this Act and the rules made thereunder:
Provided that in the case of such arrears-
(i) it shall not be necessary to issue a bill as contemplated by section 3; and
(ii) any penalty chargeable for the non-payment of such arrears on the date by which such dues were to be paid, in accordance with rules or practice as hitherto prevailing, shall be deemed to be penalty duly prescribed under sub-section (2) of section 3:
Provided further that the notice of demand for such arrears of dues and such penalty as contemplated by section 4, or as the case may be, a certificate as required by sub-section (2) of section 6 may be issued after the commencement of this Act.