HIDEN/Unknown charges on my Credit card

Took out Credit Card with Capitac Bank, I decided not to use nor Transfer any Money from it, as I wanted to close it off. As I was paying, I realized that the balance is not really going down, I then investigated it, only to find that, they charging me huge amount on Purchases & other charges on withdraws, while i was not using those services. A number of emails was sent o them to try get an understanding why, the answers was all over the place, on my push, they ended up saying those charges are from the first Month when I used the Card, I then decided to give them benefit of the doubt. this Month(May) again, I realized that same charges happened. to this Day I don't have an answer as to why I'm getting charged on Purchases and withdrawals, if I'm not using the Card at all? I will ask everyone with Capitac Credit card to check they charges!!!!