If Telkom is smart, it will drop prices to just above cost for fast broadband lines and get these lines into as many SAfrican homes as possible. Get people on the local cloud communicating for free and flatrate international connectivity. Lots of users at low price for service will result in big profits (not as insanely big as it is at the moment) that are sustainable. If Telkom doesn't do it its competition will force it to do so in the medium term.
If the SNO is however protected by government as is Telkom, it will take a little longer for this to happen. It will however happen through the adoption of technologies that cannot be legislated against or controlled by government.