Rain is awful

I got a rain sim card to test it out before my family started using it. I was planning on using it away from home for 3 weeks but starting around the 20th September. I payed the R479 with the idea that I will be able to use it until 20tb October. I stopped using it on the 14th October and in that time the internet did not work at all at my house and very poorly away from home. I got billed for the few days I used it in October and when I asked them about it they simply said I should cancel my sim card. I cannot believe that I payed full price for September of which I only had it for a week and a half and still got billed for 2 weeks of use in October. It also angers me that they debited the money from my account when the whole purpose of their service is that it is not a contract and I never agreed to any debit orders. I was under the impression that it would be prepaid and that the service would last for 30 days.