Product: Credit card or prepaid card

I opened a credit card account with Capital One with promotional offer of 0 % APR back in XX/XX/XXXX. I always made a minimal payment and had never made a late payment to this account as I was enrolled for auto-payment. I wanted to make sure that I didnt get an interest rate charge as I already paid the balance transfer fee 3 % initially. 
Given that there was ZERO information when the promotional rate would be ended on the credit statement, I called the customer representative and the information provided to me was XX/XX/XXXX. Thus, I marked my calendar to pay the remaining full balance in XX/XX/XXXX. 

However, as I reviewed the statement on XX/XX/XXXX, it stated I have a total of purchase interest rate charges of {$2200.00} starting XX/XX/XXXX with interest rate of 26.49 %. I called the customer service desk and they stated that the promotional rate was ended in XX/XX/XXXX. This was new information to me as I tried to prevent paying interest rate on a credit card. 

There were several failures on Capital One side : 1. Customer Service said the promotional rate ended date should be shown in the statement, which was false as it was never shown in a statement. 
XXXX. Customer Service said that there was a letter mailed to me last year stating when the promotional rate would be ended, which I never have received. I also signed up for paperless mailing with Capital One ; however, there was no letter was received in my inbox. 
XXXX. Customer Service told me that my promotional rate would end in XX/XX/XXXX, which was different from the statement I have. 

I have Zero access to this interest rate would go-up information but trust the information was given by the customer representative. 

I called Capital One on XX/XX/XXXX. The response I got from them was all information was in the welcome kit came with the credit card back in XX/XX/XXXX. They were NOT responsible for what customer representative said. They would not waive the finance charge and said I was responsible for entire amount. I responded that I would only pay for the principal balance of {$14000.00} and would not pay for the financial charges that was NOT my fault. I also asked the customer service address so I could mail a physical letter to them for official complaint and hoping for a resolution. I closed this credit account with them on the call. 

I paid the principal balance of {$14000.00} and mailed in the complaint letter on XX/XX/XXXX after I place the 1st phone call to Capital One. 

On XX/XX/XXXX, they charged me another {$210.00} for finance charge again. Now the account balance total is {$2400.00} solely on finance charges. 

On XX/XX/XXXX, I called Capital One customer service again about this complaint as I have not yet received or heard anything back from them. Again, they said they would NOT waive the financial charge and they do not expect to take any action responding to me. I asked if they have received my letter and they said they didn't know as that letter didn't show up in the account. I stated again that I believe my account balance should be {$0.00} instead of {$2400.00} balance solely on finance charges. Capital One still responded with no finance charges would be waived while I asked them stop charging this account while we are resolving this issue. 

I also have bank account with Capital One. If I had known the right date, I would pay off the entire account BEFORE the interest rate went up in XX/XX/XXXX. There were just so many Capital One communication failures resulted this huge finance charges. 

I am requesting Capital One to waive all financial charges so this credit card account balance will be {$0.00} and there will be no impact to my credit score.