Oriental Bank Of Commerce — no response from bank regarding chargeback

Address:

obc dewakar model school, branch ...located near m4u, 201005

On 13th april i went to obc atm to withdrawl money during withdrawl the light went and atm got stopped money was deducted from account and we complaint customer care they told us to wait for 24 hrs and they didnt registered any complaint bt the money did not came then next day they (Customer care) filed the complaint which got rejected and we went to bank branch and filled the charge back form they filed complaint thrice bt got rejected all the three time... Then they told us to register complaint online which i did.. Still they rejected and i gave the feed back now the complaint is showing in under process its been three months,.. The bank people are not responding us... So what to do now?? Is it take this much of time to get charge back??