Product: Credit card or prepaid card

I have been a XXXX customer for 16 years. I made a purchase on XX/XX/XXXX, couch sectional. The representative that was helping us, stated I can apply for a no payment or interest for 12 months. He did not state that the interest would be deferred for 12 months. I applied and was immediately approved. At the time of purchase, the sales representative ONLY gave me a receipt. I was not even required to complete a credit application to quality for the Special Promotion. There were no disclosure ever provided to me, not at time of purchase, nor by mail. 
The couch was delivered on XX/XX/XXXX but there were significant damages. We went through multiple returns and on XXXX is when we had the entire couch available to use. I have been paying {$300.00} every month to my macys credit card. The allocation of that payment was being credited towards the regular transactions and not to the 12 month special event. Again, I thought that it was because a payment was not due for 12 months, hence why my payments are not being allocated to that balance. According to a recent email from XXXX  if you wish to have an excess payment transferred to the Special Event Account prior to the last two months, you are required to call our Customer Service Department at XXXX and request that your payment be reallocated. Again, I wasnt provided anything in writing about the terms of this promotion nor that I had to call them in order for my payment to be allocated to the couches. I paid {$300.00} a month, why wasnt it equally allocated between the regular purchases and the special event account. 
I was planning on paying off the entire balance upon the expiration of the promotion. I knew the expiration was sometime in XX/XX/XXXX/XX/XX/XXXXdue to the fact that's when our couch was available for use. On several occasions in the month of XXXX, my mailbox was burglarized. A lot of mail and several packages were stolen. We have been working with the USPS and local police in trying to resolve the situation. I did not receive my XXXX statement. I paid off the couches on XX/XX/XXXX. 
On XX/XX/XXXX I received a statement and {$1500.00} of interest was assessed to my account. Right away I called and said there must be a misunderstanding, I didn't receive my statement last month, I want to pay of my card in full, but please adjust the interest to only reflect from the promotion expiration date to today ( XX/XX/XXXX-XX/XX/XXXX ) even though we didn't receive our couches until XX/XX/XXXX. Representative said no, I asked to speak with a manager, XXXX sales rep XXXX took over. She stated that the promotion starts from the date that couches are delivered and fully functional, not damaged. The couch was delivered on XX/XX/XXXX but there were significant damages, we returned it. We went through multiple returns and on XXXX is when we had the entire couch available to use. She said that no payment for the couches have been received since the purchase ( which is not true, I made a payment every month for an entire year for {$300.00}, never late ) I also asked how the interest charge calculation was calculated, and she said she didn't know since it was done by a computer. 


According to a recent email from XXXX  Beginning on the statement for the billing period ending XX/XX/XXXX, information regarding your Special Event balance was printed on page one ( 1 ) of all of your statements, along with a payoff date of XX/XX/XXXX. The payoff date for your furniture purchase is based on the date it is posted to your account. Page 1 of the statement never stated the Deferred interest, instead it only stated the amount of the purchase. I was under the impression that interest will start accruing at the expiration of my promotion instead it was deferred. Page 3 of the statement, had a deferred interest column, but again I was under the impression that thats the interest I would have been paying if I didnt have this special even promotion.