Indian Bank — atm fraud

Address:

Howrah, West Bengal, 711204

I am a customer of indian bank (Liluah branch). My indian bank details (Name-saurav ghosh;account number-[protected];atm card no-[protected]). Rs.25000 was deducted unknowingly (No otp for that transaction and no confirmation message for deduction of rs.25000 came to my bank linked registered mobile number and i had not shared any bank details with others) from my indian bank account using my atm card on 19/05/18. I had registered several complains in the bank branch (Liluah) and also loged a complain in cyber crime police station (Howrah) about it but the money has not returned yet. My doubtful questions are how can such atm transaction be possible without otp for transaction and confirmation message of deduction (As i don't use internet banking)? And how can such transaction be succesful without atm card details known by others? The bank has no answer for it...