Fraud Transaction

I have my salary account in ICICi Bank, East of Kailash branch (a/c no 071901503985). Two online transaction was done from my account on 28/02/2015 which was not authorised by me. When I informed bank about these fraud transaction they told me to file FIR and give complaint to bank. Accordingly I filed Fir and gave complaint to bank. My complaint number is SR 359846417. But they declined my complaint since it was authenticated by 3 D pin but I informed that pin was put by me and not shared by me to someone. Then how someone come to know about that and what is the assurance tomorrow someone will withdraw more money from my account. But Bank is not showing interest to solve my problems.