I also agree that consumer action *can* make a difference. Sentech is probably a good example - I think they have been hit pretty badly due to negative press (their own fault, of course, as they made a decision in the beginning to just try to ignore and deny problems and consumer complaints for two months). I suspect their rate of new sign-ups has dropped a lot, and if they don't do something soon, they may not survive. 'Inner circle' management cannot protect them from these negative effects/results of bad management.
Now, regarding Telkom, it's worth pointing out that it's not only the skilled and economically active minority who are suffering from Telkom's monopoly, the 'bottom end' of the market (who are probably mostly part of that 70%) suffers even more from Telkom's ridiculously high prices. Telkom cut off 2 million of the 2.5 million customers it installed lines for as part of a agreement with government in exchange for continued monopoly, as those people couldn't afford the lines, particularly during the inflation 'pinch' when the R/$ went 13:1. Now a lack of education in this market segment combined with Telkom's wonderful feel-good advertising campaign probably prevents these people from realising/understanding who is to blame and why (although some may use this as 'further proof' that socialism is better and that capitalism excludes the poor, but we understand it's not capitalism at fault here but short-sighted greed). But this is a public education problem, e.g. these people don't have Carte Blanche, for example. The entire country actually suffers, and has fewer jobs, because of Telkom and government's continued protection thereof, and needs to be solved by creating more public awareness and understanding of the problem amongst the 70%. Why not bring up the topic for discussion on e.g. the local African language radio stations, who collectively have very broad reach? Explain to people in the process why Telkom's monopoly is costing the country jobs (e.g. cite that Telkom's prices, 400% higher than India's, are basically the only reason that South Africa is losing thousands of potential call-center jobs to India). Compare to other countries, explain that universally, creating competition has made prices lower and given access of services to more people in other countries. Telkom harms EVERYONE in SA, not just "the whites" or those who understand what broadband is, because their management are greedy and short-sighted and simply in for a "quick buck", and they're even starting to agitate
the government itself. (Is Telkom run more by SBC or by the government?) This is why we need to coordinate such actions behind some sort of industry-created 'lobby group', who can facilitate the creation of such 'public awareness campaigns'.