Shocking service

I have been trying to cancel my cellphone contract for 3 weeks now due to terrible service on Vodacom's part. I have sent letters and made phone calls to no real progress at all. They always say that they are escalating the issue to another department but with no real progress. Now they need to waste another of my lunch breaks to check the signal strength in my house where an appointment was made for today but not anymore as the technician's car is making a funny noise so they will get back to me, whenever that will be? I refuse to pay the 1300 termination fee for a service that clearly doesn't care about the customer and has not delivered the service that they promise. I am disgusted at the way Vodacom has fallen apart and blame everything else for their short comings such as the tower facing the wrong direction, that's why I have poor signal, in town. I write this complaint in the hope that someone could advise me on where I can take this further so I can be rid of Vodacom and in the hope that others read this and steer clear of the nightmare of Vodacom.