(2) Notwithstanding anything contained in any judgment, decree or order of any court or tribunal or other authority, all penalties under the general sales tax law of any State imposed or purporting to have been imposed in pursuance of the provisions of section 9 of the principal Act, and all proceedings, acts or things taken or done for the purpose of, or in relation to, the imposition or collection of such penalties, before the commencement of this Act shall, for all purposes be deemed to be and to have always been imposed, taken or done as validly and effectively as if the provisions of sub section (1) had been in force when such penalties were imposed or proceedings or acts or things were taken or done and accordingly, (a) no suit or other proceedings shall be maintained or continued in or before any court or any tribunal or other 569 authority for the refund of any amount received or realised by way of such penalty; (b) no court, tribunal or other authority shall enforce any decree or order directing the refund of any amount received or realised by way of such penalty; (c) where any amount which had been received or realised by way of such penalty had been refunded before the commencement of this Act and such refund would not have been allowed if the provisions of sub section (1) had been in force or the date on which the order for such refund was passed, the amount so refunded may be recovered as an arrear of tax under the principal Act; (d) any proceeding, act or thing which could have been validly taken, continued or done for the imposition of such penalty at any time before the commencement of this Act if the provisions of sub section (1) had then been in force but which had not been taken continued or done, may after such commencement be taken, continued or done.