Product: Credit card

I have been an account holder for over a decade. I have always paid my bill as agreed, which is due monthly on the XXXX. On XX/XX/XXXX, I went to pay my bill online as I do every month. I noticed that instead of the ~ $ XXXX bill I was planning to pay towards, the bill was over $ XXXX, and immediately began to research the charges on the account. I observed that on XX/XX/XXXX, a {$2.00} charge was made at a local XXXX, and on XX/XX/XXXX a {$7200.00} cash advance was made at a branch. I navigated to the websites fraud claim reporting system and immediately reported the fraudulent activity, since neither of the charges were authorized by me. The bank removed the charges and began their investigation. In the interim, I discovered that the charges were made on the card that belongs to my authorized user, who is my nephew. Since my authorized user was out of town at the time of the charges due to being in a training camp, after speaking with him, and confirming he had never used nor received the card, I questioned my brother, who has the same name as my authorized user. My brother straightway indicated that he had gone into both the XXXX and the branch and had in fact made the charges on what he believed to be HIS card. He indicated that he had previously applied for a card with the same institution and was under the impression that the card he was using was his. He further stated that he went into the branch with his own ID and was never questioned about his identity. Until I mentioned the situation with my card and my authorized user, he still was under the impression that he was in possession of his own card. The bank subsequently reversed the credit and put both charges plus interest back on my card. 

I informed the bank that they did not verify the party at the branch, because had they done so, they would have realized that although the party has the same first and last name, their date of birth is not the same. I told the XXXX on XXXX of many phone calls made to the institution, that they made a mistake and gave a huge cash advance to a non-authorized party against my account. They refused to own up to their mistake, and instead accused myself and my authorized user of sending the wrong party into the branch to make a cash advance. They are now not only charging me for their mistaken {$7200.00} cash advance, but also the interest involved, which is very expensive. I have been going back and forth with the institution for several months, and they refuse to acknowledge their error. Both parties have the same first and last name, but my authorized user is solely my nephew and not my brother. Their date of birth is very similar. The one being XX/XX/XXXX ( which is my authorized users dob ) and the other being XX/XX/XXXX ( which is my brothers XXXX ). They did not follow sound " know your customer '' procedures, and as a result, they put my account, and my finances in jeopardy, and are creating a severe hardship for me in keeping up with the much higher payments associated with these unauthorized charges. The bank needs to be held accountable for their error and not charge me, a long-standing customer with their mistake. They are now reporting this higher balance to the bureaus after being made aware of their mistake. They refuse to acknowledge, and now with the higher balance on this credit card, my score has dropped XXXX points. This is a violation of my rights as a consumer, and a violation of accurate reporting. Please help me with this egregious treatment. Because it is the bank 's negligence in verifying the customer that entered the bank, which has caused me this hassle and expense.