How do the Cell C Pinnacle contracts work?

[shadow_man]

I'm looking at their website - but as usual cell phone providers suck at making it easy to understand. So if anyone can help with the following it would be great:

1.) What's the difference between Pinnacle and Pinnacle Top Up (can you not top up on the normal Pinnacle contracts?!?)
2.) Can I bolt on a data bundle? The data limits are damn low as is!

Thanks!