AJAY NATH RAY, J. ( 1 ) IN this writ application the writ petitioner claims relief against assessment of and also recovery of interest under the Central Sales Tax Act on sales which are covered by the State sales tax laws. ( 2 ) IN the case of India Carbon Ltd. v. State of Assam reported at [1997] 106 STC 460 the Supreme Court has clearly ruled that the provision of collection of interest being not a procedural provision, it cannot be lifted from the Central sales tax laws into the State laws. ( 3 ) THE writ petitioner relies on this case heavily and submits that amounts illegally collected should be directed to be repaid to the writ petitioner. ( 4 ) THE orders of State sales tax assessment including appellate orders range between December 30, 1994 and January 9, 1997. ( 5 ) ON behalf of the respondents it was submitted that where refund of money is the sole substantial remedy claimed by the writ petitioners, in such cases a suit is an appropriate remedy and not a writ. ( 6 ) THE case of Suganmal was relied upon, a Supreme Court decision given by a Bench of strength five. The first sentence of paragraph 6 (page 401 in STC) was placed from that judgment which is as follows :"on the first point, we are of opinion that though the High Courts have power to pass any appropriate order in the exercise of the powers conferred Under Article 226 of the Constitution, such a petition solely praying for the issue of a writ of mandamus directing the State to refund the money is not ordinarily maintainable for the simple reason that a claim for such a refund can always be made in a suit against the authority which had illegally collected the money as a tax. " ( 7 ) NO doubt a suit is ordinarily the remedy for recovery of money as pointed out in the above paragraph. But a suit in the instant case is bound to fail as a suit court cannot set aside an order of assessment which has reached departmental finality. " ( 7 ) NO doubt a suit is ordinarily the remedy for recovery of money as pointed out in the above paragraph. But a suit in the instant case is bound to fail as a suit court cannot set aside an order of assessment which has reached departmental finality. ( 8 ) IT is only the writ court which can undo the illegality which has crept into the assessment orders, no doubt by reason of the error in law under which all parties laboured under until the Supreme Court pointed out the correct legal position in the India Carbon case [1997] 106 STC 460. ( 9 ) THERE has not been any inordinate delay in this case either. If more than three years has elapsed from the first of the numerous orders under challenge, even that lapse of time should be excused because the three-year rule is not an inflexible rule in the writ court. ( 10 ) THE calculation of interest amounts recovered from the writ petitioner as given by the learned advocate for the writ petitioner be kept on record countersigned. ( 11 ) THERE will be rule absolute as prayed for in terms of prayers (a) and (b) of the writ petition. ( 12 ) LET the concerned respondents refund by way of payment to the writ petitioner three several sums of Rs. 1,38,942, Rs. 5,880 and Rs. 49,920 within six weeks from date hereof. There will be no order as to costs.