Dstv Rewards does not reward.. It takes from you

I downloaded the dstv rewards and in the app there was a notice for premium package at 599 for 3 months, I then subscribed and all was done. I then received 2 sms's end of this month, The one said R648 and the other R795 and the guy from your call Centre Paul assured me that it was R648 he even sms'd me the bill, I also explained that I should have been paying R599 but he said that due to the change over this was a pro-rata price. This is the second time it has happen to me, the last time I was told I would be refunded my R58 but months later nothing.