JPMorgan Chase & Co. Credit Card Complaint

JPMorgan Chase & Co. Credit card department,

Closing/Cancelling account North Carolina

I closed my account with Chase Credit Cards on - - 2016. I spoke with a representative by the name of - and asked her to mail me a letter verifying that I requested this close. I also asked her to make sure it was " frozen '' in a state on no interest until I paid the balance in full. She confirmed this. In - I made a regular payment then on - - I called in to pay my balance in full. I was upset that they never sent me a letter and logged the closure as their doing thus effecting my credit score. However, I asked the representative to give my my balance in its entirety. I paid this over the phone via my checking account. Verified again that it was paid in full and closed and was told YES. Three days later I received a bill in the mail for $10.00 INTEREST charge!!!! I called in on - - 2016 and spoke with a manager who said they could do nothing ... it was interest and the representative is not responsible to calculate this when I am asking to PAY MY BALANCE in FULL immediately????? I do not feel this is proper business practice and feel they need to eat that interest since it was my request from - to close and freeze the account!!