Saint_Dee
The Phantom Poet
http://www.mtn.co.za/Internet/GetIt/Pages/InternetPackages.aspx#
Check the R300 option, my neighbor has it and he's pretty happy with it. I wouldn't trust MTN myself, but then again all the other cellular providers are just as bad.
I've heard they throttle massively after 3GB of downloads, so keep that in mind if you go with MTN.
You could also have a look at this