Endorsement case of property, tds filling isssue

I'm buying a flat from a builder named A at X rate. Builder endorsed the flat to another party named B. Initially I paid 10% of the X amount to B, as the flat was in the name of B. Later on bank refused to give loan on the agreement of B and Me as I later got to know that flat was never allotted to B. So for loan a new allotment was made between Me and A at the amount of X-10% of X i.e. Y. I somehow agreed because I thought that the inclusion of the bank would make my purchase more safe. Later