You 'bought' your cousin (for how much)! In addition 'he have personnel loan' (for many of them?) B4 recovery he has made up his mind not to return, sounds fishy. Bank WILL and HAS TO take an action to recover the amount :-( either he or you will have to repay. If he has a Qatari passport it can be written off :-) Sell all your family investments back home and repay to avoid the severe lifetime consequences.