Random Billing

I took out a fibre package with Mweb in March 2025 of R510. I have NEVER paid R510. It's always R800 or more monthly. Their whatsapp chat takes forever to respond. There's no contact number to call them. I cannot cancel this as there's a hefty cancellation penalty. I have no idea what to budget for WiFi because MWEB makes up an amount and then bills me accordingly. I paid R630 last month and then another R50 was debited from my account a few days later and now I see that I am in arrears with R1182. ***? I am sick of this "billing system" cause clearly one of us is confused