Useless Network Provider

A complaint was made a while ago due to the pathetic service from Cell c due to them being unable to upgrade my contracts As said before I have 3 contracts with Cell c 1 of the 3 has been upgraded and now Cell C is unable to upgrade my other 2 due to credit limit as they say. I have not received any feedback from any consultant to date. I am absolutely disgusted and want all 3 contracts cancelled so that I can go to another network provider.