Product: Credit card or prepaid card

XX/XX/XXXX I purchased XXXX airline tickets ( {$540.00} each ) and {$70.00} travel insurance, total of {$1100.00} through XXXX. I used Citi Master Card ( have this card for over XXXX  years ) for this transaction. Everything was confirmed and good to go. We checked in with the airline ( XXXX XXXX ) within XXXX hours prior to the departure ( XX/XX/XXXX ) and arrived to the XXXX XXXX XXXX 5 hours prior the flight with XXXX proofs of negative Covid-19 tests and vaccination certificates. At the time of luggage check with XXXX XXXX XXXX in we were told by the lady that we can't go without any explanation. We asked for the manager and she called the young man who said that since we don't have any relatives in XXXX XXXX, XXXX, we are not allowed on this plane. Both of us are American citizens and have visas good until XXXX, but that gentleman said that the rules have changed. He gave us a business card for XXXX XXXX and suggested to call them for further explanation. He also gave us a printout with description of what is required for the destination to XXXX XXXX but it does not say anywhere that only the relatives of Russian citizens are allowed to enter XXXX. When we called XXXX XXXX for explanation, we spoke with representative whose name is XXXX and he said that his system shows that we did not show up for our flight. Then we tried to get a refund thru XXXX travel insurance ( case Claim Number : XXXX ) that replied with the following decision " Because the reason listed does not fall within the scope of coverage provided by this policy, we have determined that we are unable to extend payment on your claim. '' We called Citi Master Card and made a dispute, they refunded money the same day but after XXXX weeks they put this charge back on us. I called Citi Master Card every other day asking why and they keep telling the same thing since XXXX XXXX that we can't discuss it over the phone and that they will be mailing the explaining paperwork to us, but it's been over XXXX weeks and we did not get anything yet. Since we did not receive anything in the mail, we called Citi Master Card again and requested the explanation by email, they said it will take XXXX business days. It's been over XXXX weeks and we still did not get anything... I have never had any issues with my Citi Master Card before and was under the impression they will protect me as a customer but apparently not. They can't even give me the proper answer why am I being charged back since it was not my fault. Every time I try to reach XXXX XXXX, I am being placed on hold for minimum of XXXX minutes and then their representative is telling me to place a complaint on lot.com/ It is so unfair, I checked and XXXX is still selling the same airfare route tickets XXXX - XXXX - XXXX XXXX ) on their website. Why XXXX XXXX is telling us that we have never arrived for our flight when we have XXXX proofs of paperwork given us by their representative ( manager ) that we were there ontime for our flight? Why would XXXX ever sell the tickets that we can not use? What is the reason to buy the XXXX travel insurance if they don't cover all this mess? As of today ( XX/XX/XXXX ) we did not get any explanation from Citi Master Card why am I being charged back.