Bad Credit Card Company Who Do You Report A Bad Credit Card Company Or Bad Bank Too.?

Who do you report a bad credit card company or bad bank too.? - bad credit card company

I have a credit card from Juniper Bank. I paid the entire balance and the account closed. Now I get bills from $ 18.95. When I told the reception that the account is closed and I have 2 options for the payment of the balance or hang up. Finally, someone came and told them that the problem muttered something and hung up. Whom do I contact to sign in? Any help would be very grateful.