Fraud at SBI, bagri market branch,Kolkata.1

Last year one man seems to be from SBI came to my office after several calls and filled up one form for personal loan. He was having full details of my company . I filled up form and issued 3 cheques in name of SBI-PL a/c and one cancelled cheque , all were a/c payee crossed. To my utter experience next day my a/c was debited for Rs.85000/- withdrawn by some one Mr.patel. It was an order cheque no endorsement was there on back, no rubber stamp of my company, but the bank paid.The cheque was tampered, it observed by verifying the same , SMS came from bank after 10 minutes. I made several complaints but till date deaf ears. How a bank can pay any amount for a tampered cheque, without rubber stamp on back, signature forged on back side attestation. What duty they perform? Is this our safety?