DSTV Multichoice failing their customer.

I have had it with dstv, I took up the pricelock deal with them from January2021 and had been struggling to get them to debit the correct amount from my account. Every month they debit Doble the amount and some months even triple the amount from my account. I keep on phoning them every month and ask to speak to a manager in order for me to express my frustration but no luck. I even phoned them again today and the lady put me on hold as she was going to get her manager to speak to me, I put the phone down after holding for 20munites. I'm frustrated and don't know what else to do as they don't solve my problem. I want to know if there's other people out there who have the same issues with multichoice and how did they fix this issue.