Billing after request to close the account

It is with great sadness that i opened an account with Sterns Pretoria West, but i am still being billed without having purchased a single item using the account in question. After numerous requests to have such accounts closed as i no longer intend to buy anything from the said shop, the account is up to date not closed and i am suffering from unknown monthly charges as a result. It would be very appreciated if the said account can be closed as i never purchased anything using the account, so what are these charges being incurred for?