Unauthorized Bank Account Withdrwal Through Online Transaction

Hello,

Couple of days ago, I noticed an unauthorized bank withdrawal while checking my transaction history. This was made from my Wachovia checking account in form of an online Bill pay. The transaction seemed to show the name of Wells Fargo CC.

I notified the bank ,which was after 2 days when the unauthorized transaction took place. The online fraud division was also notified. But they seem to be very timid in their responses. They make me feel as if somehow I was responsible. A fraud investigator was not assigned to my case even after couple of hours of notification. Also the lost money has not been re-credited to my account pending investigation.

Kindly advise me what options I have. How should I proceed.

Thank you.
RR