Product: Credit card or prepaid card

My replacement credit card mailed by Citibank ( " Citi '' ) was lost or stolen and an unknown individual was able to activate the card under my account to make multiple unauthorized transactions on XX/XX/2022. I was initially alerted by the Citi Fraud Department via text and email of an attempted charge of {$1500.00} at XXXX XXXX this same day to which I immediately responded that this was not a valid charge and reported the fraud. I spoke with a representative with the Citi Fraud Department on the phone and reviewed the recent activity on my card which identified 4 other fraudulent charges ranging from {$19.00} to {$270.00} made on the same day. The representative made note of these charges and flagged them for investigation. Ultimately only 2 of the 4 charges ( both in the amount of {$19.00} ) were credited back to my account. I called Citi again on XX/XX/2022 for an update and explanation, detailing the scenario to another representative who again marked the 2 remaining charges as disputed and opened an investigation informing me that all disputed charges should have been credited back to my account. Around this same time I received a written letter dated XX/XX/2022 notifying me that the investigation and was complete and dispute closed and that the remaining two charges of {$88.00} and {$270.00} ( {$350.00} total ) would remain on my account and be my responsibility. The reasoning as per the letter was that " The card 's EMV chip was used to make the disputed transaction ( s ) at a chip enabled card reader. You verified that your card was in your possession at the time of the transaction ( s ), so we don't consider this fraudulent activity. '' Given I believed that I had just re-opened the dispute through my most recent phone call, I set the letter aside while assuming another investigation would take place. I continued to monitor my account noting no new credits had been issued, the status of the disputed charges had not changed, and I received no further correspondence from Citi. I called again on XX/XX/2022 to ask for an update on the status explaining the details once more to a representative with the Fraud Department before escalating the issue to a manager for further explanation. The manager recapped the situation with me and details of the investigation in an attempt to reaffirm their conclusion per the letter I had received back on XX/XX/2022 -- namely that the card used for the fraudulent charges had the same EMV chip as the one supposedly in my possession thus they did not view this as unauthorized activity. I first asked for clarification as to how someone besides myself could have activated the replacement card, to which she just responded that every card is different and she couldn't provide details on the exact process. She went on to explain that every card has a unique " number '' that gets picked up by the card readers, even if a replacement for a current/unexpired card ( such as was my case ), and the card used for these transactions was no different than the one I had in my possession set to expire in XXXX of XXXX  I reiterated that this was clearly not the case in my situation as I had never set foot in the stores where these purchases took place at, nor was I even close to that area of town. She was unable to provide an explanation for how the stolen card may have been read the same as the one in my possession. I continued to press for resolution and asked what my other channels for recourse were and was informed the only thing left to do would be to contact the vendors directly. As expected, I was not happy with outcome and feel Citi should be responsible as they allowed the stolen card to be activated without any input from me which makes me question the security of their process for issuing/activating replacement cards. I also take issue with their claim that every card reads as unique when used as once I reported the fraud this put a temporary hold on my account and I did try to use my card to pay for parking. Though this charge did not go through and I ultimately had to use a different payment method, it did appear as a pending charge when I reviewed my account activity with the first representative. To me, that should have provided evidence of my actual location around the same time that these fraudulent transaction took place and also would have provided a record of the EMV chip reading and the supposed unique card number that Citi could have compared with the fraudulent charges, including the {$1500.00} attempted charge at XXXX XXXX that was clearly fraudulent and first alerted me to the fact that someone was using the stolen card.