Product: Credit card or prepaid card

I used my United Explorer Mileage Plus Chase credit card to reserve a hotel room in XX/XX/2022, in XXXX XXXX, North Carolina, through the United app on my phone. I received the confirmation code by email, which confirmed my one-room reservation. Upon checking-in at the hotel, I received the information that there were two rooms reserved under my name. I explained that I had reserved just one room and that was probably a duplicate charge and asked the second reservation to be cancelled, as I was not aware there was an additional reservation, since the email I received confirmed just one-room. The hotel staff ( front desk ) said I had to call the reservation line to ask for the cancellation. Upon entering the my hotel room, I called reservation who told me I had to call my credit card company since the reservation had been done through a third-party website. I called the credit card, who told me I had to call the hotel reservation line and this became an almost two hour ordeal with one party sending me to another and vice-versa. Upon returning from the one-night trip, I contacted Chase dispute line and explained that there were duplicate charges for the single hotel room I had reserved and that I had not been able to resolve it after contacting the different parties. I paid for the one reservation I had made ( {$210.00} ) and said I was disputing the second one as a duplicate. A dispute was opened and later on I received a letter from the credit card saying I was found responsible for both reservations since I did not follow the hotel cancellation policy. I appealed the resolution In XX/XX/2022 and explained that I was unaware there were two reservations, that had reserved just one room and that was exactly what was stated in the email confirmation I had received, just one-room ( which was accurate ), therefore the dispute ( and the resolution ) could not be centered at the whether I complied with the cancellation policy or not but rather based on the fact that I had been charged twice for a single purchase and I only found out about it upon arriving at the hotel. I decided to reapply and reopen the dispute and sent a letter by mail to the dispute/fraud resolution team at Chase and attached the email confirming my one-room hotel reservation. I called the dispute resolution team multiple times and was told ( at least twice ) that the original claim had been wrongfully processed by whoever did it and that they would open a new claim and it would be resolved soon. To my surprise, I received a final letter on XXXX XXXX, 2022, from Chase card stating that " based on the information that we have available, the results of our investigation remain the same '', therefore, I continued to be found liable for the double/erroneous charge. I called dispute/fraud resolution again and requested a copy of the documents reviewed during the investigation based on what the credit card considered that I had indeed reserved two rooms. After spending 45 minutes on the call, on XXXX XXXX, 2022, and speaking with the dispute supervisor who identified herself as " XXXX '', I was transferred to the customer service team, and then back again to the dispute/fraud team. At the end, all teams told me the only documentation I could/would receive was the XXXX XXXXletter with a one-line sentence stating their investigation had remained the same. Due to the lack of trust on the credit card company I have already cancelled such credit card and have no intentions to ever deal with Chase again in any capacity. However, I was told that I have to pay for the second room reservation ( in the amount of {$210.00} ) I had not done and that the credit card will report it to the credit agencies. It is not a matter of the amount per se but the fact that a credit card can erroneously charge a consumer for what was clear a mistake somewhere along the chain that none of parties took responsibility and can blatantly deny access to the documents of the investigation to a consumer who engaged in good faith with the service provider. I am 100 % certain that there is no confirmation, anywhere, that I had reserved two rooms. However, despite my detailed explanation in a letter, the proof of my one-room reservation, my multiple calls, my request to receive a copy of the documentation, at the end, I feel like I can't do anything to stop this erroneous charge and no one took responsibility for the error and I, as the consumer, have to pay for something I did not purchase/the reservation of an additional room I did not make. I am here writing this in hopes that lack of accountability such as this will not be tolerated and that consumers will not be the one paying the price at the end.