Product: Checking or savings account

XX/XX/XXXX I called BMO Harris because I found out I have a negative DDA balance attached to my name associated with an old closed account with BMO Harris, when I called I was told that there is a negative {$5000.00} balance associated with my old checking account due to a check that was deposited withdrawn and then bounced. I informed the person on the phone that I had no clue about a {$5000.00} check, I was then told I needed to go to a branch for it to be looked into further. I went to the XXXX XXXX, Wisconsin branch and spoke with the banker XXXX. XXXX was able to locate my old account and the check that I was told about over the phone, she printed out the check and an old account statement. Immediately when looking at the check, XXXX stated that she could tell it was a fraudulent check based on the company, she then compared the signature on the check to the signature on my drivers licensee and other things I have signed with BMO Harris, which she noted wasn't even remotely similar. XXXX also compared other deposits and noted that I had never received a deposit that large or withdrawn that much money from my account and the transaction should have been flagged/blocked. XXXX asked me some questions about why I waited so long to address this because it happened in 2021, I explained to her at the time that I had a credit line with BMO Harris that was being closed that I had a balance of {$5000.00} and was working with different people with the bank to settle and pay that balance, so I assumed everything was regarding the credit account and that once I completed those payments I stopped receiving calls from BMO Harris. I only found out about the negative checking balance due to recently being denied for a checking account at a different bank. XXXX tired calling the fraud department but got no answer and told me she was going to fax the information over to that department and that she or them would get back to me. I waited about XXXX weeks and didn't receive a call so I called and was told to go to a branch again. I went to the XXXX XXXX, Wisconsin where the bankers told me that because its been so long so they wont help and I won't be able to open any other checking account until the balance was paid but I should try calling XXXX back since she originally handled it. I called XXXX and she told him that she had been reaching out to people and that they were all refusing to help because the time that had passed even though I am a victim of fraud. XXXX said it was nothing else she could do personally and gave me a phone number to call for further assistance. The number is just the general costumer service number for BMO Harris and when I call them they have no clue what I am taking about or where to even start to help and I end up getting transfered multiple times and told I am being sent to the wrong place. So BMO Harris is acknowledging that this negative balance was cause by a fraudulent check deposited in 2021 but because I didn't not take action fast enough according to them so it doesn't matter that I was scammed anymore and I responsible for something I was never informed of at the time of occurrence.