Cell C overcharged me for gprs!!

[msamito]

I was using cell c to connect to the internet the past monday on my phone. Then I called them so they may explain themselves and they did acknowledge that the was a billing error. They promised me that my air-time shall be returned to my account next day. I have been calling them everyday but even today i'm still waiting for my air-time. All that i wanna know is what is wrong with cell c. No wonder they can't even compete with the other networks