I have an iPad 2 and bought a Cell C 2GB per month prepaid deal for it. I cut the sim to micro size, and installed. All has been working perfectly, I get lovely fast 3G signals.
I wanted to keep a check on my data use, so at the start of June I went into settings - usage, and would reset the data. That works, but it means having to remember to reset the data counter at the beginning of each month.
I went into a Cell C store, and asked them how I could check on my balance, and they said it was not possible I would have to take the SIM out the iPad and put it into my iPhone 4 (micro size) and then enter *101#
Not satisfied with this response, I played around in my settings on my iPad 2 - there is a way on the iPad 2
Products and services
I see I have 2046.53 for July available. While in there, there are other handy Cell C options, where you can check RICA status etc
Hope this helps someone else