Product: Credit card or prepaid card

On XX/XX/2018, I purchased two pair of shoes from XXXX XXXX online. The total purchase was {$950.00} for both shoes. On XX/XX/2018, one pair of the shoes came apart as I was walking in them. I contacted XXXX XXXX online at XXXX. I explained to them that I had purchased two pair of shoes by the name of XXXX XXXX XXXX XXXX shoe and the XXXX XXXX XXXX XXXX. I explained how the seam on the left front gave way on the XXXX XXXX XXXX XXXX   shoe. I essentially had a break in the shoe. I sent the shoes back shortly thereafter on XX/XX/2018, because I received an email with a link for return label. I returned the shoes through the U.S. Postal Service. I received a newer pair of the shoes in the mail at my front door last week. However XX/XX/2018, I received a letter dated XX/XX/2018 from Citi XXXX Services, XXXX XXXX XXXX, XXXX, TN XXXX that they had completed an investigation of my account regarding a disputed charge listed on XX/XX/2018 at the amount of {$950.00}. The merchant is XXXX XXXX. This letter came with other documentation, which were a total of six pages. As I went through the pages, then I saw that there are various charges applied against me, and that there is a charge of {$630.00} credited and then re-applied. As I read the letter, it appears that I was being charged with {$950.00} that I am responsible for paying. What I do dispute is that I paid {$950.00} on XX/XX/2018, and as proven by my credit card statement for XXXX XXXX online. I ordered both shoes on XX/XX/2018. This letter from Citi Retail with attached information is not clear about what I owe, so I went to my XXXX XXXX account online, so that I could see what is going on. My balance is zero, but there is a XX/XX/2018 charge of {$630.00} credited and then applied again. My question is whether Citi XXXX charging me for the shoe again? Although I sent the defective shoe with original box and return label. If I owe the {$630.00}, then it should be listed and stated. I was not disputing what I paid in XX/XX/2018 for {$950.00}, which letter sent from Citi Retail Services is terribly vague. If XXXX XXXX represented by Citi Retail believe that I owe them another {$630.00} for the shoe, then they should say that, please! Nevertheless, I did not act in bad faith by destroying the shoe. I sent the shoe back to the retailer showing them how the shoe came apart on my foot. I even had the shoe examined by a shoe cobbler I use, and who determined that the shoe coming apart was a defective issue in manufacturing. I bought seven ( 7 ) pair of shoes from XXXX XXXX over the last year, and not one pair of shoes came apart on my foot like the XXXX XXXX XXXX XXXX XXXX shoe. I wear my shoes from XXXX XXXX   often, but apparently my story and evidence sent back to XXXX XXXX and investigated by Citi Retail did not agree with my determination about how the shoe was considered defective. I sent out also two letters on XX/XX/XXXX and XX/XX/XXXX. I also cc 'd the Chief Executive Officer of XXXX XXXX, XXXX XXXX XXXX. I believe the confusion surrounds the belief that Citi Retail believe that I am disputing the {$950.00} charge, which I never said I did. I bought the shoes. I paid for them, but the XXXX XXXX XXXX XXXX   shoe came apart while I was walking down the street in XXXX, Connecticut. If I returned the shoe, then should I have been charged for another pair? I don't believe I should, but if XXXX XXXX wants to charge me again, then I want the CFPB to determine if this is considered legal and ethical. I go out of my way to pay my bills. I am by no means a delinquent payer of my credit cards. I have evidence of all of the letters i sent and letters received from Citi Retail.  I think a larger question should be if a shoe is defective and sent back to XXXX XXXX, then why is Citi Retail investigating a product that they are only responsible for financing access to the product, and they are not responsible for determining the efficacy of the product 's performance and endurance through the manufacturing process. Apparently, all of the information that I sent to XXXX XXXX Card Services XXXX XXXX XXXX, XXXX XXXX, SD XXXX was ignored. Did anyone at XXXX XXXX actually look at the shoe, or was the shoe examined by Citi Retail? When I look at the paperwork sent from Citi Retail, then the charge of {$630.00} applied and credited shoes that they received the shoe, but no determination of defectiveness was assessed.