South Africa has a telecommunications act which specifically covers the use of amateur radio and includes the frequencies being used for wifi: 2 300-2 450 MHz and 5 650-5 850 MHz. Amateur radio is essentially a community owned network which is operated by licenced amateur radio operators. There might be a way to justify a community wireless LAN network as part of an amateur radio network. There are certain rules such as not using the network for business purposes, charging for the service or transmitting music. You also need to a basic proficiency exam, which includes writing morse code at 12 words a minute (ouch!), to become an amateur radio operator.
If you want more details on Amateur Radio regulation in South Africa
ICASA telecommunications act for amateur radio
And more about the National Association for Amateur Radio in South Africa
South African Radio League Home Page
If you want to write the exam
South African Radio League Exam