Product: Checking or savings account

On XX/XX/XXXX I contacted Citizens banks to dispute a {$350.00} transaction that I made via XXXX for a seller who never sent me the merchandise through XXXX XXXX. Citizens Bank " investigated '' the claim and determined that the claim was legitimate. I knew that wasn't the case because the seller never me any tracking information and the seller had also blocked me on XXXX. It was clearly a fraudulent transaction especially when I have not received the item. After calling Citizens bank at this point 2 times to figure out the status of my claim and finding out that it has been denied. I decided to send my evidence which included correspondences with the merchant and the XXXX transaction that proves by the preponderance of the evidence that he had no intentions of sending the item to me. Between XX/XX/XXXX and XX/XX/XXXX, I have contacted citizens bank approximately XXXX times to get this issue resolved and my {$350.00} refunded to me. On XX/XX/XXXX ( which was dated XX/XX/XXXX ), I received a letter from Citizen 's Bank that despite the evidence that I've provided that their original decision to deny my claim stands. I was not happy about this as {$350.00} is a lot of money to lose. The evidence that I sent to Citizens Bank clearly showed my correspondences between me and the merchant. Immediately on XX/XX/XXXX, the Monday when I made this phone call following the incident between me and the XXXX which happened on Friday, I checked my transaction to see if it went through. At that point the funds were still on hold before going through to XXXX. I contacted XXXX a day prior on Sunday as Citizen Bank customer service was not open around the time I called them. They told me that they would investigate the claim. They never gave me a claim number. I called them a couple days later and they told me that they couldn't refund me the money because the merchant had already received it and they told me to work it out with Citizens Bank. I am at a dead end with trying to figure out what I can do to get my money back. I strongly believe that because I shared my evidence which proved that the merchant had no intentions of sending my money back and that I called immediately after the merchant blocked me on social media that I am entitled to receiving the {$350.00} for a DJI Mini XXXX Pro drone that I have never received. I've never had to fight with Citizens Bank like this. They've asked me to work with the merchant. How can I work with the Merchant after he blocked me on social media? Citizens Bank clearly can see that through the evidence that I sent them. I've been a customer with them for around or about 13 years and I've never had this issue with them. In the past when I've disputed transactions under similar circumstances I would typically always get my money back. In the past Citizens Bank would always have American customer service representatives. I've noticed that Citizens Bank are now outsourcing their customer service representatives from XXXX, which does not have a good reputation when it comes to computer related customer service. Having to contact Citizens Bank about XXXX times is absolutely ridiculous. Numerous times I was told that I would received within XXXX hours a phone call from Citizens Bank regarding my claim and even there fraud department even told me that they would give me a call back and never once did I ever receive a phone call from Citizens Bank. I always had to contact them myself. There is absolutely no excuse or reason with the evidence that I provided for Citizens Bank to deny my claim. I really want my {$350.00} back.