Debited for something I dont have

I have been a DSTV subscriber for 15 years plus, I responded to the promotion for the DSTV explorer by sending an sms to the relevant number, it took over a week to get a call back. I eventually got a call and went through the relevant credit checks. The contract was approved and I was advised that someone would be in contact with me to confirm delivery. I am yet to receive the call and needless to say, I do not have the Explorer Decoder. This morning I received notification by my bank of debit orders, Checking these I notice that I have been debited for my existing DSTV subscription and the new contract for the explorer (Which I do not have). I contacted the call center to be advised that there was nothing that can be done about it now and that the query will be escalated. This type of error is really not expected from a company like Multichoice. I want the debit order reversed and confirmation on when I will be receiving my explorer. I also want a guarantee that when I eventually receive my explorer that the existing contract with Multichoice is cancelled and the new contract put in place and that this error never happens again.