Can't cancel contract because of incompetence!!

10 October 2014 I cancelled my contract as Neotel requested a 20 day notice. They told me that a cancellation fee of R 1230.30 was payable to cancel. I rep**** to them asking the question why I should pay as they were not delivering the service promised and my internet was of a very poor quality (0.50 mbps). I complained about this before and I was told there is nothing they can do as the area has bad reception. They rep**** that a consultant will get in contact with me - I'm still awaiting this consultant's phone call!! I'm still being billed every month although I stopped using the service end September 2014. I still ask the question: Why did they proceed with accepting me as a client full knowing that the area I reside in has poor coverage? I subsequently changed service provider where I get double the data (20 mbps) at half the price Neotel was charging me!! Still, they don't even bother giving me a call!!