Possession of my flat

Q: I have done all the formalities with HDIL and for loan with Dewan Housing Finance Corporation and my loan is already approved and check is also ready with Dewan Housing Finance Corporation but they ( Dewan Housing ) need clearance letter from Central Bank of India from which DHIL have taken loans against this property to clear the check. Now since last one year we are trying to get the letter from HDIL and their management and staff is giving promises only. And thus we are not able to get this letter and thus possession of my flat. At the time of approval of loan the HDIL also took around 5 lakhs from me as a taxes and charges saying you have to clear this first and apply for loan. Now I am living in Saudi Arabia and cannot come everyday to follow the case my brother is following with them but he is also tired now. what option I have and what can I do now is anyone to help me out..please...