Discovery card stay away bad news

in August last year I cancelled my Discovery card Despite having filled in the forms Discovery continued with deductions and charges this year I three times contacted them and explained that I have cancelled and require the amounts in the account reversed and all charges reversed as well. Eventually the amount in the account was reversed however the charges did not. When I enquired I was told oh well there is no money left in the account so sorry for you. The service is pathetic at best and I need to know that they will refund me the charges as promised initially.