Citibank Personal Loan
Unneccessary calls for recovery of personal which my brother never availed from Citi Bank

My Cousin Brother who is a bussniness man recently started receiving calls from CitiBank Personal Loan call center executives regarding the recovery of personal loan which he has never availed from any of the bank .. :) It seems like some fraud person has used his detail for availing the loan from citibank and cheated the bank but isn't it a mistake of bank too?? Why they have not done the proper verification? Any ways kindly help me by providing the Citibank Personal Loan Escalation matrix... Thanks & Regards,

Nafees