Poor service from DSTV

On 9 October 2019 I wrote to DSTV about my subscription. I have been paying R425 for the past year or more. At the beginning of September they debited me R539.90. When I rang DSTV no-one could tell me why the amount was increased. At the beginning of October they debited me with R529. I received an automated response to my letter of 9 October which gave me the reference no: *** and that I would be answered in 8 working hours. It is now 16 October and I have heard nothing since. I am a 75 year old pensioner with limited funds and to suddenly debit me with an extra R100 really hits me hard. Nothing has changed in my DSTV so I cannot understand why the sudden increase. According to recent media, they seem to be having a problem with their billing. In my letter I asked them to correct my debit and refund the excess amount which I really don’t think I should be paying. Maybe that is why they didn’t answer me.