Worst bank in the world (FNB)

I Closed my FNB cheque account almost a year ago just to recently find out that it was never closed. I no longer have any working card for this account, no money is being paid in to it and yet i am being charged a monthly account fee. the account is almost R2200 in arrears because they refuse to close the account. according to the useless in branch staff they cant close it till i have paid the arrears amount. i refuse to pay for something I have not used. they also wont stop or freeze the account and every month keep adding to the arrears amount. this has now affected my credit score in a negative manor and I am unable to get any financial assistance from my current bank.