Product: Checking or savings account

On XX/XX/2023, someone stole my debit card information and tried to use it fraudulently. Luckily, the transaction was blocked and no money was taken, but to be safe I ordered a new card. The card arrived in the mail, but when I activated it, I discovered it was attached to the wrong account so I ordered another card. That debit card was stolen out of my mail box on XX/XX/2023 and the thief used my card to drain my bank account. Seven fraudulent transactions occurred for a total of {$3800.00} that was stolen from my account. Navy Federal Credit Union ( NFCU ) notified me of a {$500.00} transaction occurring which was when I checked my account and became aware of the other charges. I responded to the alert to let them know it was not me using the card, and I immediately called the bank and opened a fraud claim with NFCU so they could investigate the fraudulent transactions. 
Fortunately, the mail thief who stole and used my debit card was arrested by the XXXX XXXX XXXX XXXX who then contacted me by coming to my home on XX/XX/2023 because my familys mail was found in the suspects car. The authorities also told us they had found my card on the suspects person at the time he was arrested, and they had obtained video footage of the suspect using my card. They suggested, due to the amount stolen, that I file my own police report as well which I did with the XXXX XXXX XXXX the same day. I provided NFCU with the arrest report number ( XXXX ) from the XXXX XXXX XXXX XXXX XXXX XXXX as the case number for the police report I filed with the XXXX XXXX XXXX XXXX XXXX ). NFCU then denied my fraud claim. 
When I called NFCU to ask why my fraud claim was denied despite the evidence I had provided, I was told that the arrest report and police report information that I had submitted were not reviewed because, due to processing errors, the information was not attached to my fraud claim until after my fraud claim had already been denied. To have my claim reopened so that the evidence could be reviewed, I was advised to submit an appeal which involved me telling the whole story again as well as providing my evidence again. My claim was denied by NFCU again. 
NFCU notified me that my claim was denied due to conflicting information. They would not provide me with any details about their investigation or what it was that they considered to be conflicting about the information I provided. They will not allow me to appeal again or reopen my fraud claim. 
The evidence I have submitted can be verified with the authorities I have mentioned. XXXX XXXX XXXXXXXX at the XXXX XXXX XXXX XXXX can be contacted directly to verify that fraud has occurred : XXXX, XXXX. Please see the attached police report from the XXXX XXXX XXXX for further details. 
I do not believe my fraud claim was investigated at all by NFCU because if it had been then there is no reason why my claim should be denied. This was verifiable fraud. The bank did not even contact me to ask me any questions. The only communication I received from the bank about my claim were the two fraud claim denial letters they sent to me. If there was any confusion about the information I provided, then I should have been contacted by the bank so that I could be given the chance to clarify whatever it was that was in question, not simply denied without explanation. My fraud claim was not handled appropriately, if it was even investigated at all. I was dismissed without any reasonable explanation. I want my fraud claim reopened, and I want evidence that NFCU is taking this matter as seriously as it should have been taken in the first place.