Cell c - disgusting service

Well after writing a desperate review to obtain assistance from cell c I was quite relieved to receive a call from a nice lady from cell c from the technical department who informed that I could cancel my contract with them with no penalties as it was a tower problem . She promised to return my call, guess what I'm still waiting for her call. I shouldn't be surprised as they continue to show why I think they r a useless service provider. They cannot provide a service so I want to cancel my contract. I did receive calls from customer service providing me with "feedback" to say the tower was a problem due to eskom. Really for a whole year!!!! No resolution to my problem!!!! I have also asked them to put through the call to the lady that initially called from the social media department - but they have no number for me to phone. What can I do now?