I think any other business besides a monopoly would have shut their doors a while ago with these prices.
I think the only way adsl will survive in south africa for the average home user is if they drop the access fee to zero and up the entry level speed to 4mb.
ie pay R139.00 per month (throw in some free airtime minutes) and give adsl connection at 4mb at least. (users will then buy their databundles where they get the best deal)
If they do not do this I would guess their future will be short as most home users will move to 3g/hspa I have no doubt.