Product: Checking or savings account

On XX/XX/XXXX I checked my Wells Fargo checking account. There was initially {$800.00} in the account but I noticed a teller check was cashed for the amount of {$770.00}, which left {$25.00} remaining in the account. The transaction couldnt have been done by me because I was a XXXX XXXX at the time and was on the road with no access to a bank. The account is a joint account with my ex girlfriend and the relationship had been over for over a year. So I contacted the other person with access to the account and she said that she didnt make a withdrawal from that account either. I filed a claim through Wells Fargo and at that time they closed the account the transaction was made from and opened a new account. They reimbursed the {$770.00}. Along with the {$25.00} remaining in the closed account, {$800.00} was transferred to my new account. At that time I transferred the funds to another account I have with the same bank ( Wells Fargo ). Shortly after, I checked the online banking again and at that time I noticed the {$770.00} was withdrawn from my account again which left my account in overdraft - {$770.00}. I called Wells Fargo back and they said the investigation was still in process and it would take up to 10 business days to complete, so I transferred the {$770.00} back into the overdrawn account. On the tenth business day XX/XX/XXXX, still not hearing from Wells Fargo yet, I called back and they said they couldnt find the claim that I filed because it was closed and a letter was sent to my mailing address to explain. Once I received the letter on XX/XX/XXXX I realized that it wasnt for the correct claim. The claim the letter was sent for was a {$300.00} claim that I cant recall filing. I was told my only option was to file another claim on the new account because they said they didnt have access anymore to the closed account or its transactions. Also, when I went to check the transactions on my online banking the transaction now says withdrawal from branch instead of teller check which is what the transaction was initially labeled as when the fraudulent transaction was made. I waited the 10 business days they told me the investigation would take. They didnt call me so I called them on the 10th business day, XX/XX/XXXX and was told my claim was denied because the signature matched the signature they have on file. Once again, I was out of town and didnt have access to a bank to make a transaction or provide a signature and the other person authorized to use account reassured me that they were not responsible for the transaction either. I do not have any paperwork that can prove exactly where I was at the time of the transaction, but I can confirm that I was working for XXXX XXXX XXXX based out of XXXX, TN and that I was actively working in the northeastern region of the country ( Ohio if Im not mistaken ) at the time of the transaction. I can also get a written statement from the other authorized user of the account. But shes an ex girlfriend from almost a year ago and I was reassured that she hasnt made any transactions using the account in question. Lastly, I asked them for information on where the transaction took place so that I could try to investigate on my own but they did not have that information.