Mtn Taking Payments more than agreed

I signed a contract with them and the agreement was to pay R200 but they always take more even when I don’t use the data. They have not given me and feedback from my escalation cause they only care about the money and not customers, I was called by them and was offered a contract on promotion with the router device being free but when I wanted to cancel the contract they said the device is not free, their agents lack customer service skills nor knowledge. I asked for a call recording from when they called but it’s almost a month but nothing, how can I escalate this further cause I can’t keep playing more than we agreed on for data I hardly even use