Bad service from cell c

Cell c has been robbing me of airtime on 3 different occassions. The first time I called them up and after 4 weeks R10 airtime was refunded. The second and third time, I haven't had any response from them. The people at the call entre are dumb. They really dont know whats happening. The cell c network is absolutely terrible. Every single day there is a problem with the network. As far as my airtime is concerned, I dont think I will ever be refunded. Cell c - just plain down rogues. If it happened once, I would have said its a mistake. I only noticed 3 times. How many times has this happened before unnoticed and to how many people, only cell c knows.