Rain internet

CANCELLED RAIN BUT STILL BEING CHARGED My issue with Rain is the signal is very bad phoneed numerous times complaining but no feedback or solving of my problem. We went over to another user end October not using rain anymore. Today they deduct R1800 offof my account. Tried to contact them with no answer on their side and debit can't be reversed at my bank. How gave them permission as I paid the money over monthly as they couldn't deduct from their side. But now out off the blue they can. I'm very disappointed in their service. I need to end this deduction due having a new internet service provider, and cant pay double How do I stop this????