Product: Checking or savings account

Between the month of XXXX and XX/XX/XXXX, I received mail from Wells Fargo, reporting my account was overdrawn over {$6000.00}. I went to the nearest branch where I opened my account to know what happened. The bank personel who assisted me did not gave me adequate response but answered me malicious look and response without looking over to any of my account activities, blaming me right away why my bank account got over drawn or hacked. When I feel I am not getting the right answer, I asked the bank personnel who's the right person should I talk instead to dicussed my situation further. After I got the information I went home and called the person right away to discussed the issue. 
After awhile a lady from that Investigation/ Medition department answered and discussed to her what happened and told me to give her sometime to investigate and she or her colleageu will call me back. Weeks passed no calls, so I called the lady. She told me to give her more time. After several days she called and this time she's blaming me as well like the branch personnel first spoke, trying to get away to be liable with what happened. I mentioned that no one gave me any allert or suspecious activities in my account like the normal way the bank was giving email or message when something wrong is going or to confirm if its me or I authorize that transaction, plus even I will do it myself, the ATM machine can not pull out over {$300.00} of my ATM withdrawal, which was my max ATM limit to withdraw. So how can I withdraw that over {$6000.00} during after office hour? There so many lapses with the bank employee and systemfrom this issue. Definitely they make mistakes and their system and just trying to make excuses and blame me instead. Plus my account should be covered by bank insurance which they can not denied, which they also asked if I insured my acount. I don't need to asked them, they should authomatically insured all depositors in any bank? 
The lady from mediation asked more time to call me back, but soon after she never gave me convincing feed back and just trying to give me some unrelated excuses and just keep asking same questions over and over again. Later she failed to called me back and giving me hard time to reached them. My XXXX XXXX get worst and forgot to give them a call. 
Last XXXX of XXXX I received a call from same mediation team of Wells Fargo, asking if I signed an insurance last XXXX of XXXX or XXXX regarding to insured my bank account. I told her all depositors should be authomatically be insured by any bank. She didn't go further after I said that and just mentioned that the insurance will send me {$500.00} as a settlement of my loss. I said I loss more or less {$14000.00} plus the inconveniences it gave to my situation. I was partially XXXX those time, still under recovery of my XXXX. She explain I can still accept that check of {$500.00} and they will attache mediation form for me to fill up for what ever I loss and concern. Weeks, month passed no checks and remidiation form came. 
XX/XX/XXXX, I received a mail with check of {$520.00} and mediation form. I filled it out and send back to them. XXXX XXXX, XXXX, another mail came with check of {$340.00} and mediation form again. Still I filled it out and send it back. XX/XX/XXXX, another mail came saying they received the copy of mediation form I sent to them and will contact me as soon they need further information. XXXX passed and XX/XX/XXXX, i received their mail, saying they are trying to contact me by phone to discuss the specific of my mediation claim and possibility of resolving my claim. I have no idea if that's true since they failed me several time in our previous meetings.