Incorrect billing

Can someone please tell me how this DPP thing works??? Because when I signed up, I paid an upfront R849 which was to be credited to my account. Now I've had a D/O of R1,104 come off my account. As far as it was explained, residential billing Should've stopped (R779 Premium that I pay/paid monthly) and DPP start but only a month later with the ad hoc payment being credited. ***?! Unfortunately at the moment alternatives for Multichoice are in short supply. I've had