Time.
It'll be at least another twenty years before the ANC is in serious danger of losing a national election and until then the corruption that has become South Africa's biggest problem can be fixed, or at least replaced by smart corruption that does more than simply line pockets but actually gets things done as a quid pro quo for staying in power.
Well, true, but what solutions could be done for SA to succeed in the present? What laws/acts could be passed?
SA has reasonably good laws on the books, but if they aren't being applied fairly and uniformly, good laws aren't the solution. It'll take a change in the political culture of South Africa for them to make any significant progress beyond where they are, and that change is unlikely to happen so long as the ANC can continue to rest on its well-deserved laurels from the struggle against apartheid. Ending that will take time.