Wifi limit increased without consent

Applause goes to Cell C for increasing the limit on my WiFi account without my approval. This is after I asked for it to be capped. Mysteriously now nobody at Customer Care can see who or how it was increased. But I must still pay the bill AFTER IS WAS PROMISED on 01 January 2019 and given a reference nr that it will not happen again. Guess what!?! Debited me more then double again cause the limit got increased again with out my approval or consent. Now when I want to cancel this, I must still pay a cancelation fee... I would not cancel if CELL C can just respect their customers enough.