While I agree that the local leg is still costly, alternative options as well as self built networks are pushing costs down. I'll point to the fact that the arrival of Seacom pushed ADSL from ~R70/gb down to ~R20/gb and later brought uncapped, yet none of that saving has found its way to the mobile networks. Vodacom business attributed savings for its ADSL customers to Seacom way back when it landed, yet Vodacom didn't pass anything on to the consumers. Seeing as MTN didn't blink nothing needed to be done to the pricing (as has always been the agreement). WACS is also just around the corner, while not as drastic, I'm expecting more love for ADSL users when it goes online and nothing for mobile users.
The point is that I didn't have to look far (albeit elsewhere in the world) to find pricing that Vodacom and others claim is unsustainable. I'm sure I could find cheaper if I had the time, it was just convenient that the prices happened to be from Vodafone (hey even the colours match now

). The other point is that if it's doable elsewhere why are you not following the "world class" benchmark and pushing to achieve those prices? It's so obvious with the current MTN and Vodacom promotions that Cell C has rocked the boat and rather than taking the lead, band-aids are being applied in the guise of promotional deals.
The other atrocity is that nothing is being done by either provider to help their existing clients. If you are currently paying R389/pm for 2G and have 12 months to go on your contract, though luck Mr. Customer! We only care about new clients and those at end of term who are thinking about jumping ship.
Again all these actions (or inactions) just highlight how well MTN and Vodacom have done to control the market and look after their most important assets: Their shareholders.