Home Depot review: credit card 24 month deferred credit promotion

Two years ago on November 26, 2017 I went to Home Depot here in Houston, the Willowbrook store looking to purchase flooring. I found the flooring I wanted, the sales person's name was Dolly. (I have the original paperwork and sales receipt showing the discount). They had a 24 month deferred interest promotion. I told the salesperson I did not want the promotion in case it couldn't be paid off in 24 months instead I asked for a 10% off discount. Dolly called Citibank while in my presence and was told it had to be done at the time the purchase was rang up. Dolly then called the person who was the store manager at the time and was told to give me the discount and gave her instructions, she said, to ring the purchase up. We went to the front of the store to customer service and she rang the sale up herself and I was assured the promotion would not be applied.

I have been making payments on my account for two years thinking I was paying the interest along with the purchase month to month only to find out two days ago November 27, 2019 when I received my new statement due Jan 10, 2020, that two years back interest had been applied along with additional over the limit fees, etc. have been applied as well. I called Citibank and was told two bad the promotion was applied anyway without my knowledge or consent and you have to pay off $2100+ for the flooring. They said it was the stores problem. I called the store and was told they had no control of those promotions they belong to Citibank although I was given the discount in lieu of the promotion.

I am 69 retired and trying to refinance my house but won't be able to make these outrageous payments I thought I would not have and will now cost me hundreds of dollars in lower interest on my house because of the negative reports on my credit bureau reports and won't be able to refinance my house.