The South African situation is very nuanced. The ANC had a violent faction, and a more peaceful faction aimed at reconciliation. The well-known Nelson Mandela belonged to the latter faction. Note that I said "more peaceful" and not "peaceful." Nelson Mandela also participated in sabotage attacks during Apartheid.

Those two factions are still alive in the ANC now that it is the ruling party. It just takes a different shape now that violence isn't the modus operandi anymore. You could call it a far-left radical faction, and a moderate faction. The far-left radical faction is heavily influenced by Fanon, they openly admit it. Also on the far-left you have the EFF (Economic Freedom Fighters) who were kicked out of the ANC for being too far-left. They also claim to be Fanonian. They are openly calling for violence, while simultaneously denying that they are calling for violence.

The violence prevalent in South Africa is caused by a wide array of causes, of which I expect Fanonian thought to be one of the lesser causes (but a cause none-the-less). A bigger cause is an inept and corrupt government by a political party that is still stuck in revolutionary rhetoric 30 years after it's victory. Their inept and corrupt governance caused degradation in law-enforcement, to the point where it is almost non-existent. Pair this with the abject poverty and fatherlessness caused by Apartheid, and you have yourself an unruly and violent populace.

Fanonian thought only factors in when things get political. In my opinion that is less commonplace than the media (both mainstream and otherwise) suggests. Our violence is mostly just normal plain old crime.