DSTV BILLING CHARGES

I have been overcharged on my subscriptions since November 2017. On Monday, 17 February 2020 I contacted DSTV and was advised that I should have been billed the PRICE LOCK rate but was billed more. I was also charged for Xtraview which I do not have. To date they have not refunded me nor can the call center tell me how much I will be refunded. It is very frustrating.