Car track- unauthorised debits

So i signed up with car track early this years. The consultant insisted on taking my banking details even though i said i was going to pay full up front. He said its a requirement. After i deposit full amount for subscription i received sms showing debit order off my account. I immediately called in and another consultant assured me that the problem will be rectified and did not understand why the first guy insisted on banking details when it could have been signed on as cash contract. To my dismay the i am still being billed Debits orders are coming off my account monthly i have contacted the office on several occasions but to no avail. Please assist i need this stopped immediately. Looks like i will have to cancel this contract.