Explorer not collected / Double billing of account

I ordered the explorer 20 November. They gave me an R899 deal but I subsequently found out that the R849 deal is better value for money. I phoned them on 23 November and asked if they can cancel the R899 deal and give me the R849 deal. They promised to get back to me. They delivered the Explorer late on 23 November despite me having asked them not to. I called them to say that they need to take it back as I cancelled that deal. they gave me a Reference number *** for the DPP division to call me and collect the unit. The DPP division called me but to date (2 December 2015) nothing was collected yet. This morning they debited the normal R780 PLUS the R899 despite me not having the explorer installed. I'm very unhappy with their service because when I phoned I get transferred from one to another. They also pretend that they can't hear me...this morning I immediately took down the person's name I was talking to \Theodora"who did the same and I said to her"