Dstv failing to refund over-charge

In June 2018 I activated my Holiday decoder for 1 week. They over-charged me R4941.60 for the one week. I have called over and over for my refund. Each time they acknowledge they owe me the money but it needs to be bumped up to their supervisor and I will be paid as soon as that has been done.

I am still waiting for the refund but they keep charging me every month. How do I get my refund. Will move to streaming movies from next month instead and stop paying for Dstv.