I don't think you understand the situation or the other posters' comments completely. Forget for a minute about minimum wage and all that. Let's look at how a company works: You have a board of directors and share holders. The board works effectively, for the share holders. If the board decides to enrich themselves, the share holders start losing out and have the choice of getting rid of the parties responsible.
When will the share holders start losing out? When the company starts performing poorly due to, for example, over worked or unhappy staff with low levels of productivity. The board can continue paying themselves massive bonuses while their staff are unhappy, but eventually they're going to get kicked out, or the board can give the employees raises or hire more staff and let the company continue to perform. It's not like the guys at the top aren't held responsible for their actions.
Now, to get back to minimum wages. A basic rule of economics is supply and demand, right? Now, at the moment, two guys both have R10, for example, and they want to buy a bread each. The problem is, there is only one bread. Both of them really want it and whoever's selling the bread knows there's a big demand for it. The seller charges R10 for the bread because he knows he's going to get it and sells it to one of the two guys.
Right, so now minimum wages get hiked up and these two guys now earn R20. They both want to buy a bread. The seller now knows he'll sell it, but since more money's available, he can charge more and he jacks up the price to R20. Did either of these employees gain anything by their salaries doubling? No. If everyone's salaries get pushed up, everything will just get more expensive since that's what retailers can get away with, not to mention the added cost of producing goods due to employees earning more, etc. The increases end up being artificial and inflation goes up.
You cannot artificially alter the supply/demand (In this case skills) relationship with regulations and whatnot and have it be sustainable. In the end, you're just bluffing yourself. Increases only work when a select portion get them, if everyone gets them you haven't achieved anything other than getting more zeros on your paycheque.