PRICE LOCK OVERCHARGE

I signed up for a 2year pricelock agreement in February 2018 for R959 per month and together with a monthly insurance premium of R35 on he decoder, the total came to R994 (account no. ***).. For almost 18 months evrything went smoothly, every month the correct amount of R994 was deducted from my account via debit order. Then all of a sudden in September 2019 everything changed, Without any explanation, an amount of R1216.42 was debited to my account - over charge of R2222. On 16 September, I contacted DSTV Customer Care in this regard and was told that the matter would be escalated to the relevant department and that the amount would be reflected as a credit on my next months bill. But no such luck, next month came along and not only was the credit not processed but I overchrged again with R64 - an amount of R1058. Again I phoned DSTV Customer Care on 17 October only to be told again that the matter would be escalated to the Price Lock department for resolution. Today I contacted them to get an update on this issue only to learn that nothing has as yet been done. The consultant infact advised us to contact the Price Lock department ourselves via their SMS line to sort the matter. The lady informed us that she only deals with new business and we should phone their Price Lock Billing department. She provided their supossedly phone contact numbers but this turned out to be a fax line. So what now, where do I go from here? I am totally frustrated with DSTV and their so called customer care(less). So much for their "No price increase for 24 months". Cant wait for my price lock contract to end next year, will definitely not be renewing.. Just don't trust them anymore, they just do what they want whenever they want to.