cotton fabrics," (b) woollen fabrics", (c) "rayon or artificial silk fabrics" or, as the case may be, "man made fabrics", shall for all purposes be PG NO 789 deemed to be and to have always been, as validly and effectively made, issued taken or done as if the provisions of this section had been in force at all material times and, accordingly, notwithstanding any judgment, decree or order of any court, tribunal or other authority (a) all duties of excise levied, assessed or collected or purported to have been levied assessed or collected before the date of commencement of this Act, on (i) "cloth", "cotton cloth" and "cotton fabrics" subjected to any process, (ii) "woollen fabrics" subjected to any process, (iii) "rayon or artificial silk fabrics" and "man made fabrics" subjected to any process, under any such Central Act shall be deemed to be, and shall be deemed always to have been, as validly levied, assessed or collected as if the provisions of this section had been in force on and from the appointed day; (b) no suit or other proceeding shall be maintained or continued in any court for the refund of, and no enforcement shall be made by any court of any decree or order directing the refund of, any such duties of excise which have been collected and which would have been validly collected if the provisions of this section had been in force on and from the appointed day; (c) . . . . (d) . . . . " 8.