Builder asking more money.

I had bought House in Badlapur(Mumbai - India). I had done registration on 1st July 2010.

Now when i am taking the possession he is asking of  for below money.

1. Service tax 2.587%

2. VAT  1%

3. Interest = 18 % on registration amount.

Please let me know which are compulsory needs to pay. Is there any problem by builder about above details...Whether he is taking extra money from us.

Please reply .. Whether builder is asking more money from me..

1. What is 18 % interest on Registration amount. I am hearing this first time.. till last month builder had told nothing about this to us. But now he is asking for same.

2. About service tax , whether this budget eliminate the service tax from property.