No joy from account support

I've requested my account to be closed, but after each month I get a statement, query it and get a ticket created by customer services and a day later get a mail that the ticket has been resolved, only to get another statement, with more charges (card insurance/interest etc. no purchases) on the account. On querying the last time they said it cannot be closed because the balance is not 0, a balance that was clear when I requested the account to be closed. Since I'm not getting any helpful response from the channels they provide, I've decided to go a more public route.