Cheating In Car Selling

i bought an old car from my well known person the car was under loan from a bank which was told to me that i need to give decided amount and that owner will give me n. o. c from bank within 6months but now 6 months has gone i m shocked that tge car still has a loan amount approx 4lacs on it. i have a notary affidavit from that person in which these terms conditions were decided, what should i do to claim.... or what can b done..