MTN South Africa is currently working with Apple to finalise the required testing to support LTE on the iPhone 5. This is according to Kanagaratnam (Lambo) Lambotharan, Chief Technology Officer at MTN SA.
iOS 6.1 brought LTE support to many additional markets around the world, but MTN SA was not included in this support.
For an Apple device to be supported on a local LTE network, Apple and mobile operators must first reach an agreement (which includes testing and other issues), after which Apple will release the config files and enable LTE support on those networks.
Lambotharan said that they will make the necessary announcement to the market after the required iPhone 5 testing has been completed.