Car Selling Woes !

I,ve a car which is hypothecated to a bank. Now I wanted to sell my car and I put up an ad for it. A certain gentleman contacted me and and we agreed to sell my car at Rs 2,50,000/-. My present due with the bank is Rs 2,00,000/- , I told him that , he paid me Rs 50,000/- (as advance) Ive a xerox of the agreement and said that he is taking a fresh loan for the used car from the same bank . He also made me sign off Form No.28,29,30 in his favour (except the money receipt )and an authority that he can pick up the NOC on my behalf. After 2 days he sent me a e-mail that a loan has been sanctioned in his name.He has to just complete the paperwork . Now today 10 days has passed and he is not coming over phone and an agent on his behalf keeps on giving me fresh dates when he will foreclose the loan . Meanwhile he also wanted to take away the car which I didnt allow i.e. the car is still with me.And honestly I dont know how to react or do I need to take any legal step? I dont think he can change the ownership pre-hypothecation clearance ?