Telkom Charge me for what they cannot offer

This has been going on forever now, and I am at the point of no return. I am sorry but Telkom will never see a single cent out of my pocket ever again. I had this complaint with them sooooo long ago, and the thing that gets to me, like so many other services in this country, if I don't follow up, remind, fight, complain, nothing will be done. Telkom are charging me for a DSL service that they cannot even offer in my suburb. I am being charged for a 4Mbps service, but they will apparently only be able to give 4Mbps to me by the end of a guestimate date of 2016. So, I am getting a line speed of 2Mbps, and the quality of the line does not even help me get even close to that speed in any event. Now, there is an amount outstanding, because I refuse to pay more than double for a service that makes me want to slash my wrists every time I use it. I am a Systems Architect, and already installed other means of internet at my house, and will stop at nothing convincing every person I know to not use Telkom, and that there are many other lights at the end of the tunnel.