I don't understand if you're trying to be sarcastic or not. If not, then all good. If you are...
Dishonest or fraudulent conduct by those in power, typically involving bribery - Oxford online dictionary.
Charging 200%, as long as you charge everybody that, is not bribery, dishonest or fraudulent. Charging 200% to a Classic patient, and 500% to a Gap cover patient, is most certainly corruption.
Ultimately, there are only so many hours in a day. If your doctor wants to make R10000/day, he can see 10 patients at a R1000 each, or 20 patients at R500 each. Which do you think's going to get the better care?
Coincidentally, the most corrupt guy I know, charges medical aid rates only. The difference is, he charges the medical aids for every thing he does, and then some. Let's say you need your gallbladder taken out. In order to do so, they need to loosen some adhesions first, but it's really part of the same procedure. Doctor A charges 200% for the gallbladder removal, but doesn't charge anything for the adhesions, because it's part of the op. Doctor B charges 100% for the gallbladder and 100% for the adhesions. They take home the same amount, but doctor B cost the medical aid more, and that's what's driving your premiums up.