Product: Credit card or prepaid card

Detailed Description : On XX/XX/XXXX I purchased {$1000.00} of merchandise at XXXX ( Order # XXXX ), All merchandise was purchased by me, for me, received by me, and charged to my XXXX Credit Card, On XX/XX/XXXX I returned, using XXXX labels provided by XXXX, merchandise totaling {$590.00} ( ALL purchased with my XXXX  credit card ), On XX/XX/XXXX I received 3 emails ( @ XXXX, XXXX, & XXXX ) from XXXX customer service confirming receipt of {$590.00} of merchandise returned from Order # XXXX ( see attached copies of emails ), I immediately noticed that the email sent from XXXX Customer Service at XXXX on XX/XX/XXXX reflected that {$90.00} would be refunded to me as a XXXX Gift Card, At XXXX XXXX XX/XX/XXXX I called XXXX Customer Service and spoke to a XXXX trainee representing herself as XXXX and I made it clear to XXXX that, o the {$90.00} in merchandise was purchased by me using my XXXX credit card, o XXXX had no legal authority to provide a refund to me other than by the original purchase method, which was my XXXX credit card, o Under no circumstances would I accept a {$90.00} gift card as a refund for the merchandise, and o I would accept no method of refund other than a full refund of {$90.00} to my XXXX credit card since that card was the original method of purchase. 
At approximately XXXX, XX/XX/XXXX, after being on hold multiple times while XXXX consulted with numerous supervisors, XXXX assured me that she had corrected the XXXX mistake and the {$90.00} would be refunded to my XXXX credit card instead of a XXXX gift card. 
On XX/XX/XXXX ( 4 days before the XX/XX/XXXX Payment Due Date ) I made an electronic payment of {$410.00} to XXXX  ( see attached bank verification ) for the full amount due on my XXXX account ( {$1000.00} - {$590.00} of returns = {$410.00} ) ( NOTE : I am aware that with a keystroke error I paid you {$0.00} more than the total amount due ; meaning I SHOULD have an account credit in that amount ) Sometime in XX/XX/XXXX I began receiving voicemails indicated that the caller was attempting to collect a delinquent debt to XXXX. After completing a XXXX search of the phone number, as well as a search using my XXXXXXXX . XXXX app, I learned that the phone number was a scam ( see attached ), and I chose to ignore the almost non-stop calls. 
On XX/XX/XXXX I received via USPS a Collections letter ( attached ) reflecting an overdue amount of {$280.00} ( {$90.00} + accumulated interest + late fees ) to XXXX. 
On XX/XX/XXXX at XXXX I called XXXX Customer Service and after insisting that I speak with a Supervisor I was ultimately transferred to someone who represented herself as XXXX . After spending much time explaining the situation, XXXX informed me that she could not help me and transferred me to Citibank At Citibank I spoke with someone claiming to be a supervisor and presenting herself as XXXX. After again going through the events and the documentation I had in hand to prove my points, XXXX assured me she had removed all accumulated interest and late fees from my XXXX credit card account but told me there was still a charge of {$90.00} due that represented merchandise purchased that only XXXX could reverse. I was then transferred yet again to XXXX Customer Service After being on hold forever, I finally spoke with a XXXX Customer Service representative who presented themselves as XXXX. After spending many, many minutes again explaining the situation to XXXX, I was informed that he could not help me and would have to transfer me to XXXX ; which he very abruptly, and rudely did. 
After again being placed on hold for many, many long minutes I spoke with a customer service representative at XXXX who presented themselves as a supervisor by the name of XXXX. After many, many more long minutes of explaining the situation to XXXX, and the written documentation I had in hand, she informed me that she was finally able to find the history of the returns and would process a {$90.00} credit to my XXXX credit card. However, she would first have to get approval from another supervisor. Many, many, many long minutes later I was transferred to XXXX supervisor, XXXX. 
While admittedly XXXX appeared to be more competent than anyone else Id spoken to, it still took forever for her to approve and process the {$90.00} credit to my XXXX credit card. And after spending more than 3 hours on the phone with your and Citibank staff, she informed me that it would still take 24-72 hours before the credit would be reflected in all XXXX and Citibank records ; and that the collection calls should stop after that period of time.

Not only am I still receiving collection calls as of this writing, but on Saturday, XX/XX/XXXX I received a paper statement from XXXX ( attached ) that indicates that I now have a delinquent balance of {$200.00}, instead of {$280.00}, and that my credit limit has been reduced accordingly. 
After receiving my XX/XX/XXXX statement I am at a loss for words