Product: Credit card or prepaid card

On XX/XX/XXXX, I opened a Wayfair and received a line of credit of {$1500.00}. My purchase was for {$1400.00}. I purchased items on a promotional offer which was no interest until XX/XX/XXXX. Based on this offer, {$1400.00} was due to paid by the XX/XX/XXXX to avoid interest. 
I had made payments each month and the minimum payments were approximately {$52.00} per month. During the time frame I had made bigger payments as well. I made my payments via XXXX online from the same account every month via bill pay. Bill pay from XXXX allows me to provide my Wayfair acct #. Once I set this up via XXXX, XXXX send the payment to Wayfair. My bill is due on the XXXX of each month. I made a payment on XX/XX/XXXX of {$100.00} via XXXX Bill pay. 
On XX/XX/XXXX, I called to pay my final bill, close the account, all while avoiding interest. I called Wayfair at XXXX PST and they were closed for the day. The promotion ended XX/XX/XXXX. Then I called back on XX/XX/XXXX at approximately XXXX PST, and spoke with a female Wayfair Representative. The representative advised I could make a payment today ( XX/XX/XXXX ) and would not be charged interest. She reassured me that since XXXX was an issue, the company would be lenient, especially if done today. The representative advised that she could not take the payment and I had to go to the automated system. She couldnt transfer me, so I had to hang up and call back. I called the automated number and entered my RT # and CHK #. I received a confirmation number. The confirmation number is # XXXX XXXX XXXX. To my delight, I had closed the account with no intertest or additional payments due. I had not heard from Wayfair until XX/XX/XXXX. 
On XX/XX/XXXX, I received a phone call from a female Wayfair representative advising that my account was past due in the amount of {$35.00} plus late fees which was a total of {$82.00} due. I advised her the account was closed and that a payment was made on XX/XX/XXXX. The Wayfair representative advised that XXXX informed WAYFAIR, they could not find an account that belonged to me. According to Wayfair, On XX/XX/XXXX, XXXX allegedly returned the check in the amount of {$850.00} to WAYFAIR because XXXX didnt have an account based on the numbers. The representative then asked when a payment could be made and I advised her that I would call her back. 
On XX/XX/XXXX, I called XXXX and they advised there was no recent activity sent to Wayfair. The XXXX payment to close this account didnt come out of the checking acct. 
On XX/XX/XXXX, I spoke to female Wayfair Presentative first and then I spoke to a male supervisor by the name of XXXX. He advised that he listened to the recoding from the automated system on XX/XX/XXXX and that I manually entered my account information incorrectly. XXXX read the incorrect numbers to me that I allegedly entered in the system but did not offer to provide the correspondence from XXXX. Wayfair reiterated the number was incorrect which is why the funds didnt go through. 
XXXX advised that I should have called and that it was nothing that he could do. He offered to remove the late fees ONLY. Now I also find out, my account is no longer XXXX past due, the total bill is over {$1000.00}. This is interest from the promotional offer, the payment and late fees.