Horrible service, wrong billing, no after sales follow up

I am a new customer at MWeb (Well I thought my contract will only start on 1 October as my current service provider will stop their service on 30 September).

MWeb informed me that they can only start once the IP address is available (30 September). I consented to that as we cannot afford to pay more than one internet provider per month. It was explained to me that MWEB cannot start until the current provider ends. I agreed to that arrangement. Then they installed our new rooter, which will come with our contract (once again - it cannot word until we have the IP address). Then we were billed R200 and a week later R500. Great were our shock - the new technology allows MWEB to start with their service immediately (under other circumstances I would jump for joy) But NO ONE explained THIS to us! We did not agree to start paying immediately. And all of a sudden our sales consultant is no where to be found. How do I sort out this mess? We cannot even use the internet as no-one explain how to log in! I don't want to use it anyway as I cannot afford to pay for this until 1 October!!!!!