Billed for no service!

I signed up for a new service on the special offer of no increase for 2 years. I told the Sales Person I am moving into a new property in the due course of April so the service should not be activated before installation has taken place. I send multiple emails which were confirm that it has been sent to their DPP department who will deal with it. I never received confirmation that they should not bill me, as they can see and know my services are not active for this contract. However as I feared they debited my account last night with R1 200! So what should I do about this, Many years ago I experienced that Multichoice has this habit of debiting your account just as they want with any amount that pleases them, I actually feared this would reoccur with my new contract, and so it did! I want to cancel everything as I have no confidence in bloodsucking institutions who *****s from you!!!