Incorrect bank caherges

Discovery Bank have being debiting my account with a card I do not possess. I have the following refernce numbers ***,***,***,***,***. Each time I call I get promised that I will be called back. I have now made 5 calls to the Discovery Call Centre and have not yet had a return call. I have not been able to get Discovery to stop the debit wqhich is now happening every month or to get these incorrect chartrges reversed.