P.R. Raman, J.

Petitioners were assessed to building tax in respect of the building bearing Nos.6/990A, AI, A2, A3, A4 and A5 of Mattancherry Village. The land was purchased by the petitioners in 1982 and thereafter the building in question was constructed in 1983-1984. The building has a ground floor, first floor and second floor. For the purpose of assessment, the plinth area of all the floors were taken into account and the entire building was taken as the unit of assessment. Though the petitioners had a contention that each floors should be separately assessed treating it as a separate building, the said contention was not accepted by the authorities and the matter has already become final. As such, this question does not arise for consideration. The building tax was assessed under the Kerala Building Tax Act, 1975 based on the return filed by the petitioners. It was assessed to tax at Rs.9,853 fixing the total capital value of the building at Rs.3,33,608/-. Petitioners were served with a demand notice under S.10 of the Kerala Building Tax Act on 16.12.1986 and the petitioners paid the said amount. There was no appeal or revision against the order of assessment. While so, a demand notice Ext.P4 was served on the petitioners under date 17.3.1988 calling upon the petitioners to pay a further amount of Rs.5,249.56 alleging that the earlier order of assessment Ext.P3 is irregular causing a loss of Rs.5,249.56 to the Government and the District Collector, Ernakulam has directed the Tahsildar to revise the assessment order and to recover the loss of the aforesaid sum. Accordingly, a revised assessment order under S.15(3) of the Kerala Building Tax Ordinance, 1974 was also enclosed along with Ext.P4. This notice, evidently, is issued in a printed form and no revised order of assessment said to have been enclosed along with Ext.P4 is either produced by the petitioner nor by the respondent. On a perusal of the file also, I find that other than Ext.P4, no other order was passed by the Tahsildar. According to the petitioners, they received only Ext.P4 along with Ext.P4(a) demand dated 18.3.1988. From the order Ext.P4 itself, it is evident that though this notice was issued under S.15(1) of the Kerala Building Tax Act, the basis on which the order is issued is as a result of the direction issued by the District Collector stating that the earlier assessment is irregular causing a loss to the Government. However the petitioners, without a whisper, paid the said amount of Rs.5,249.56 in installments as allowed by the authorities. In the absence of anything to show that the said amount was paid under protest and in the absence of any appeal or revision filed against the said order Ext.P4. I must proceed on the basis that Ext.P4 having been satisfied by the petitioner, the same has become final and it is not now open for the petitioner to challenge Ext.P4. However, the Tahsildar issued a further notice Ext.P6 dated 14.3.1990, more than 3 years after the original assessment order Ext.P3, but within three years after the revised order passed Ext.P4. By Ext.P6 notice, again the Tahsildar informed the petitioner that the assessment made earlier as per Order No. B.T.Nos.17 to 24/86 is irregular causing a loss of Rs.75,729. Obviously, therefore, the Assessing Officer proponed to rectify the original order of assessment which according to him was irregular. Ext.P6 further shows that the Tahsildar was not exercising the power under S.15(1) of the Kerala Building Tax Act independently, but was rather subjected to the dictation by the higher authorities as evidenced by Ext.P6 itself. It is stated that it is because of the direction of the Government and the Accountant General as per Order No.SRACHQ/IV/LR 21-671-88-89 dated 7.7.1988 to revise be assessment that the proceedings to recover the loss was initiated. Though Ext.P6 further informs the petitioner to appear before the Tahsildar for a hearing and to file objections, in so far as Ext