Problem in sale deed

Helli sir, I am Akshay shah living in pune & 8 month back I have purchased resale flat in pune, I have done agreement to sale & paid all money 34lakh except loan which is 15lakh & the owner has already loan in punjab national bank of 34lakh But after doing agreement to sale we come to know that owner already has done MOU which is notari on same flat 1.5year back & has taken 11lakh rs from him but now he is not paying him back so there is case going on my owner because of that I am not getting NOC from society. & other important thing is owner not clear the loan amount also he not pay single rs to bank still the loan is on my owner name & he is paying emi. So now my problem is my sale deed, NOC & bank loan not clear Only thing I have is possession of flat. Sir Please guide me what should I do.