Rain is nowhere to be found

I informed Rain on the 25th July'20 that I would like to cancel my simcard and their service as their wifi was too slow, measured 0.21Mbps. I received an automated response after cancelling on the app that it would be done wef 1st August'20. Come 1st August 2020 and I got surprised when they billed R250 from my credit card. I have been trying to contact them to ask for my refund but until today I can't get hold of them. I tried their Support Contact on the app and email but no luck. I don't have their address, and I don't know where their offices are. Their app is already showing that the next billing date will be on 1st September 2020, I don't know for what service because the simcard is cancelled as I requested, it worked until 31st July' 2020.