Product: Credit card or prepaid card

This complaint pertains to the failure of Citibank to remove an unauthorized charge on my Citibank XXXX XXXX XXXX  Mastercard. After alerting Citibank of an unauthorized charge on my Mastercard account. Citibank simply closed that Mastercard account attempted to open a new Mastercard account in my name, transferred the unauthorized charges to the new Mastercard account and attached additional fees and interest to the new Mastercard based on my not paying the original unauthorized charges. 
The initial billing error was for charges totaling {$150.00} on my Citibank XXXX XXXX XXXX Mastercard with account no. ending in XXXX. The {$150.00} charge includes a charge of XXXX plus a fee of {$28.00} plus interest of {$2.00}. These charges have since been transferred to a new card having an account no. ending in XXXX. Additional fees in the amount of {$39.00} and interest in the amount of {$3.00} have been imposed by Citibank bringing the total alleged balance to {$190.00}. 
This card was originally issued by Citibank as a Sears card and was then renamed by Citibank to XXXX XXXX XXXX   Mastercard. My last transaction on this Citibank Mastercard was on XX/XX/XXXX for {$4000.00} wherein I paid this account off in full. Until the unauthorized charge occurred, the only communications I received from Citibank were the updated Mastercard ending in XXXX ( which Citibank initiated ) and various advertisements. Since I do not use the card, I did not have an online account for the Citibank Mastercard. 
On XX/XX/XXXX I received an email from Citibank XXXX XXXX XXXX MASTERCARD indicating that my account was past due. ( Copy attached ) I was alarmed because I have not used this card since I paid it off in full, almost one year ago. I also have not received any statements from Citibank concerning this card since I paid it off in full almost one year ago. 
After receiving the email from Citibank, I made many attempts to create and access an online account on XX/XX/XXXX. I was eventually able to create a Citibank online account to retrieve copies of statements for this Mastercard. I found that there was a charge for {$110.00} to XXXX, which I am very sure I did not make. I checked my XXXX  account online to confirm any credit cards that may have been used for subscription purposes, and I was able to verify that the only credit card I have ever used with XXXX is an expired Visa, not the Citibank Mastercard. The subscription service I had with XXXX expired years ago. ( A copy of that verification is attached ). 
In short, I have not made any charges on this Citibank XXXX XXXX XXXX MASTERCARD since I paid it off in full almost one year ago. In addition, this Citibank Mastercard is not being used for any subscription billing purposes. The initial charge of {$150.00} on these Mastercards are in error and so are all additional fees and interest. I called the Citibank fraud protection line on XX/XX/XXXX to alert them of the unauthorized charge but was told by the Citibank representative that they would be sending me a letter which I never received. The representative offered me no help what-so-ever. Then, according to Citibanks written guidelines, I submitted a timely, written notification disputing this unauthorized charge, via express mail. In response Citibank posted a letter to my online account indicating that I am not responsible for these unauthorized charges. ( Copy of Letter attached. ) However, Citibank then closed my initial XXXX XXXX XXXX  Mastercard ending in XXXX and attempted to open a new XXXX XXXX XXXX   MasterCard for me ending in XXXX to which they simply transferred all of the unauthorized charges. ( Copy of Statement attached. ) They have also locked me out of this new Mastercard account online. So, I can not dispute this charge online.