Tethering has been working since the 3.1.1 upgrade as the Vodacom settings for MMS & Tethering are built into the firmware.
This means if you are on MTN or CellC, you more than likely will not have access to tethering or MMS, as each time you sync, the settings are "overwritten" with the Vodacom settings. It won't work any other ways, by applying hacks etc, won't get you tethering.
To allow internet tethering to work, you need to have access to the iphone.vodacom.za APN, which needs to be activated by Vodacom, either through the call centre or Vodacom4me website.
As Gambit mentioned earlier to reset your settings can can do the following: Settings->general->Reset->Network Settings
With regards to VVM, this also relies on the iPhone APN, so you need to have that activated when turning VVM on. Again, this will obviously only work on Vodacom. With regards to Price, I agree R10 isn't too much, but agree it should be built into the Vodacom iPhone package.