For an Apple device’s LTE functionality to be supported on a cellular network, Apple and the operator must typically first reach an agreement and the service has to be tested by both parties.
After the process has been completed successfully and Apple is happy with the outcome, the company will release the config files and enable LTE support on that network.
To date this has not happened for the iPhone 5 in South Africa, but it may change with the release of iOS 6.1.
Speculation is rife that iOS 6.1 will be released by the end of January, and this release is likely to include an expanded list of LTE approved carriers. Vodacom and MTN may well be included in this list.
If this turns out to be correct, local iPhone 5 users in the major cities will be able to experience higher speeds on their smartphone through South African LTE networks.
Source: My broadband – Press Release – 9 January 2013