I've been saying this for years... the only way forward for radio in South Africa is pirate radio.
Commercial radio is all about the lowest common denominator - that means they will play whatever is perceived as most accessible to most people. It automatically rules out 99.9% of good hip hop which is perceived as 'edgy' and 'niche'. You cannot expect corporate radio to play good music without pressure from 'independent broadcasters' (pirates) stealing their listeners (and therefore their advertising revenue).
We only started getting specialised radio programming in the UK after years of pirate stations leading the way.
The internet is still way too inaccessible for most people so podcasting isn't going to be a viable channel for independent music for years to come. Joburg council is just starting an initiative now to bring real broadband to the citizens of Joburg for an affordable price,,, sadly it won't come into operation for another 4 or 5 years.
Setting up a pirate station is cheap and easy. Yes, it's illegal, but since when has that stopped anyone. If you want independent media, you have to create it yourself... or you just have to be happy with whatever crumbs you are thrown from the table of commercial radio.
