Taxation

I HAVE BOOKED A INDEPENDENT HOUSE IN 2012 WHICH COSTED ME APPROX 3300000 RS. POSSESSION OF WHICH WAS GIVEN TO ME IN FEB 2103. NOW AFTER FOUR YEARS OF POSSESSION BUILDER IS ASKING FOR VAT OF APPROX 143000 RS. IN POSSESSION LETTER IT WAS WRITTEN THAT NOTHING IS PENDING AGAINST ME. IN THIS CASE AM I BOUND TO PAY THE VAT.\ 2. SECONDLY THIS HOUSE IS INDEPENDENT 2BHK HOUSE ON WHICH BULDER HAS TAKEN SERVICE TAX ON ENTIRE AMOUNT. RECENTLY I HAVE LEARNT THAT GOVT HAS EXEMPTED THE SINGLE RESIDENTIAL HOUSE VIDE A NOTIFICATION ISSUED IN JUNE 2012 DESPITE OF THAT HE TOOK SERVICE TAX FROM ME. I PAID APPROX 90% OF THE MONEY AFTER JUN 2012. YOU ARE REQUESTED TO PLEASE GUIDE ME IN REGARDS TO BOTH THESE QUERIES