Product: Credit card or prepaid card

I opened an XXXX store credit card by XXXX in XX/XX/XXXX. I made one charge to XXXX and paid it off in XX/XX/XXXX. 
On XX/XX/XXXX a charge occurred on this account for {$21.00} which I did not authorize and was unaware of. 
I opted out of paper statements and never received any email communication or statement from them. 
XXXX  charged me a late fee in XXXX and then another late fee in XXXX, XXXX. After checking my credit, I became aware of the charge and late fees in XX/XX/XXXX, I called XXXX to discuss the fraudulent charge and fees and the fact that I never authorized the charge etc., they removed one of the late fees but told me that they could not remove the negative report on my credit. They would not remove the initial unauthorized charge and I paid the amount to keep it from accruing additional fees and interest. The account was reported to the credit bureau as 30 days late several times. I asked them at that time to close the account upon receipt of my payment for the unauthorized charge and late fee. This did not happen. 
Also in XX/XX/XXXX, XXXX began charging me a {$2.00} ( " minimum charge '' ) without my knowledge. I was charged the same fee in XXXX as well. When asked about this fee during my call to them in XXXX, they stated the fee was because I had a XXXX ( XXXX ) balance on the account. I paid those fees in XXXX as well to avoid further problems. 
I was charged again XX/XX/XXXX, and then charged a late fee of {$2.00} and then another " minimum charge '' of {$2.00} in XX/XX/XXXX. In XXXX, upon finding out that the account was still open and I was being charged fraudulently AGAIN, I paid the {$6.00} to avoid any further issues with my credit, called them to inquire about the charges and fees and requested -- DEMANDED -- AGAIN that they close the account. 
I do not receive paper statements or digital communications from them for this account AT ALL and assumed ( as I should not have ) that the account was closed as requested. 
Upon getting turned down for a credit purchase in XX/XX/XXXX, I checked my credit report and noted that this account WAS NOT CLOSED and was in fact still open and that an ANOTHER fraudulent charge was charged to my account in XX/XX/XXXX and my account had accrued more late fees. 
I have reported in writing to XXXX that the new charge again is unauthorized, and is in fact fraudulent, the account should have been closed. They responded today, XX/XX/XXXX, that they JUST NOW closed the account and refuse to look into the unauthorized charge and will not refund the late fee. 
I have several store cards through XXXX  and have impeccable credit with them, I have paid on time and have not had issues with any card or service like I have with this card. 
This account has not only ruined my credit but has caused me to pay fees that I do not owe just to keep from ruining my credit further. They have not communicated with me properly, refused to close the account as requested, refused to properly review the account upon the report of unauthorized charges and finally have reported inappropriately to the credit bureaus. 
I am now afraid that requesting to close this account with the unauthorized charge outstanding is going to cause additional harm to my credit. 
PLEASE HELP!