On Air is a big ****!

I regret the day I took a 24 month contract with On Air as they promised to deliver and install the device. I have been following up with them for the installation with no luck. Instead I was asked if I want to change the installer. Every time I phoned them I hear stories from their in experienced consultants. I'm just been told that if I want to cancel the contract I have to pay R150 for the delivery of the decoder. This is all wrong as they did not commit to their contract.