You can lodge a complaint to the nearby branch of that particular bank’s atm with a written application. Accountant will verify his cash log during end of the day process and if there is a mismatch in atm transaction your money will be refunded within 2-3 working days.
This same happened with me and branch manager told me to wait for 24 hours and if the money is not refunded then you need to visit the branch with invoice which you might be got while withdrawing the money from ATM and meet someone, who process the refund and it will be credit within 4 to 5 hours In the account.
