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

While Citi has agreed that there has been ongoing fraudulent activity on my accounts, I am being blamed for one of the purchases despite continuing to provide evidence to the contrary. Most recently, I received a written response from Citi regarding this case on XX/XX/2022. Since the written response, Citi has been ignoring my emails and not returning my calls regarding this situation. 

Citi is claiming that I made the fraudulent purchase and had the card in my possession because I confirmed the last 4 digits of the card number, and because the credit card was listed on my online account. Citi also stated that the card was added to the online account on XX/XX/XXXX, which is also the date they previously told me the card was sent to me. I have the USPS Informed Delivery feature set up, so an email is sent for every single piece of mail that is scanned by USPS, even if we do not end up getting the mail, such as if it is later stolen like in this situation. The email attached shows that the USPS did not scan the piece of mail that contained my credit card until XX/XX/XXXX. I would not be able to activate a credit card that had not even been processed by USPS on XX/XX/XXXX in the manner that they are claiming. Additionally, they also had previously told me that they sent the card then so it could not have been in any way possible for it to be in my possession the day they say the card was added to my online account. 

As I have stated multiple times, I accessed the last 4 digits of the credit card from my online account ( not from having the card in my possession ), and that card was automatically added to the account, just like all the previous cards had been. Before Citi blocked access to my account, I was able to see the last 4 numbers of all of the credit cards that had fraudulent purchases that had been sent to me and not received. The only card I ever physically added to the online account was my very first card. With each stolen card that Citi confirms was not in my possession, I only knew the card number from the online account and never added those cards to my online account either, yet they showed up. I have never in my years long history of owning multiple credit cards through different companies ever added a new card to an existing account. The cards are always automatically added and updated. 

Citi can very easily look at the date the card was shipped and see that I could not possibly have added this card to my online account or had the card in my possession on XX/XX/XXXX, and can look at the email below to show that there is no possible way I could have had the card in my possession on that date. The piece of mail attached also has a number on it that can show that this is the card in question. Additionally, Citi can easily check and see that all of the cards sent to me that were not received and contained fraudulent purchases were all listed on the online account. Citi is not making any effort to actually investigate this situation and is trying to charge me for a {$1600.00} purchase that I could not have possibly made. I would like to also point out that a purchase made that very same date, within the same hour and in the same area was deemed fraudulent, while I am being blamed for a single purchase. Additionally, whenever I provide evidence Citi changes the reason for why they are blaming me for the purchase, even when it literally does not make sense and is impossible and then ignores me. They also continue to block access to my online account and claim it is for security purposes, however, I had access to my online account for all of the other fraud cases as this has been an ongoing case spanning multiple credit cards.