Complaint sub-issue: Credit card company isn't resolving a dispute about a purchase on your statement

I had originally purchased a trip to XXXX through XXXX on my Citi credit card in XX/XX/2020. I had accidentally chosen the payment plan instead of paying the full amount. I made 3 payments toward the trip and then paid the balance off in full on the 4th payment  only days before XXXX cancelled my trip. Customers were instructed by XXXX to contact their financial institution and file disputes to receive refunds. I contacted Citi and filed a dispute on each charge, my initial payment of {$190.00}, 3 payments of {$140.00}, and the final payoff of the balance for {$420.00}. I received a flight credit through the airline for a completely separate amount from my flights, which was fine, so I did not dispute that charge. After months of waiting, Citi did permanently credit my 3 payments of {$140.00}. The initial charge of  {$190.00} and the final payment of {$420.00} were both found in the merchant 's favor and they reversed all conditional credits associated with those amounts. I spoke with Citi. They told me the {$190.00} was found against me because I took too long to return the paperwork. I didn't understand what they meant at the time, but I let it go initially and proceeded to provide them everything they asked for because I thought the dispute had been reopened to be corrected. In regards to the dispute for {$420.00}, they said I had not completed the appropriate document sent to me, except they had never sent me the document. All correspondence sent to me from Citi in regards to any and all disputes is in the communications section in my account, unable to be altered or deleted, and that paper is never listed anywhere as being sent to me. The girl I spoke with said she would handle it and send me the necessary document. I immediately filled it out and sent it back. When they denied my dispute for the third and final time, the woman I spoke to was extremely rude to me and told me that I was beyond the timeframe that allowed me to dispute the charge even though I had began the dispute in XXXX. The initial girl I spoke to listed a date of XX/XX/XXXX on the paper she emailed me in XXXX! I was never once informed they needed any additional documentation for it until XXXX and I returned it to them by the next day. I had previously sent them my entire itinerary with XXXX, including all charges and payments processed. I was informed that there was nothing Citi could do for me in regards to the {$190.00} and {$420.00} and that they would be closing the disputes with absolutely no option of reopening it. When I asked the woman to prove to me that they had sent me the paperwork in a timely manner and that I would let the issue go at my own fault if they had, she insisted their system showed they did, but was unwilling to provide any kind of proof of that. I have contacted the police in Florida against XXXX as well as the Attorney General in both Florida and Pennsylvania, like thousands of others who've also worked to get their money back, in my attempts to recoup the money that XXXX took from me while they rendered absolutely no services to me. XXXX also did not reimburse me XXXX XXXX, as they stated on their " updated itinerary '' that they initially provided Citi. I sincerely hope that you are able to help me. Thank you.