Capital One Bank Account Or Service Complaint

Capital One Bank account or service department,

Checking account Using a debit or ATM card Maryland

there were fraud checks deposited into my bank acct ( Capital One ) and an ATM withdrawl of $480.00 that Capital one bank is holding me responsible for. the ATM withdrawl was done in IL. I called and reported my card lost and the fraud on my acct. Capital one is holding me responsible for the $480.00 withdrawl that I did not make. they are also ending our banking relationship saying I am a liability. how can I fight this? All my funds are on hold.