Bad customer service

I have purchased 200 items minutes and 200 data. When I tried to make a call it said I don't have enough airtime. When I checked my balance there was a 0.00 balance. Called Cell C to find out what happened to my minutes Andy they told me I can only purchase Cell C airtime with the airtime I purchased. There was no message online stating that it is only for Cell C to Cell C calls. They told me they can't change or convert it to normal airtime. I advised that I am going to take this to the papers and make a big nose about it and they never cared. If this is what Cell C calls service then they really stink.