Are there any books that seek to explain the demise of South African Aparthied from a Materialist point of view?

You should try to start in the '70s. This was when the ANC was almost entirely in exile and new social movements got going in South Africa outside of their control. Once you understand this, the '80s and '90s (and the lack of reform by the ANC since it gained power) starts to make a lot more sense.

1973 Durban General Strike:
https://libcom.org/library/strikes-durban-1973

The growth of the Black Consciousness Movement, Steve Biko etc., then the Soweto uprising:
https://libcom.org/library/year-fire-year-ash-soweto-revolt-roots-revolution

Then very late '70s you get the institutionalisation of some of these currents with FOSATU and AZAPO (haven't read this one but found it instead of the article I was looking for):
https://libcom.org/library/future-hands-workers-history-fosatu

Could then go backwards from there to '40s/'50s struggles or forwards to things to post-apartheid movements like Abahlali baseMjondolo https://libcom.org/library/homemade-politics-abahlali-basemjondolo-south-africa-s-shack-dweller-movement

The ICC has produced a series on the history of the class struggle in South Africa:

http://en.internationalism.org/internationalreview/201402/9459/history-class-struggle-south-africa

http://en.internationalism.org/international-review/201508/13355/south-africa-world-war-ii-mid-1970s

http://en.internationalism.org/international-review/201702/14250/soweto-1976-anc-power-1993

http://en.internationalism.org/content/16598/election-president-nelson-mandela-1994-2014

Birdigists - it's true we fly above all the rest. But we're not Bordigists. See this:
http://en.internationalism.org/the-communist-left

'Official' is not the happiest of terms but the idea behind it is that there are different currents within anarchism, expressing the influence of different social classes. There are genuinely internationalist and revolutionary tendencies (see for example this article: http://en.internationalism.org/wr/336/anarchism) which are definitely part of the proletarian movement; there are others - whether inclined towards lifestylism or terrorism - which express the position of the petty bourgeoisie; and there are others who have joined up, in one way or another, with the forces of capital, from the anarcho-Trenchists in World War One to those parts of the CNT which participated in the bourgeois republic in Spain or who paraded at the front of the allied imperialist forces reoccupying Paris in 1944; or who, today, act as cheerleaders for Kurdish and other forms of nationalism. Just calling yourself an anarchist is not enough to avoid the powerful ideological pull of this system - and of course, the same has applied, again and again, to those who have seen themselves as marxists. This is the main point of the article linked to in post 6: that you have to understand the real historical dynamic of a political current to identify its class nature, above all in the way it relates to the absolutely fundamental question of internationalism.

Vlad, you're trying to squeeze blood from a turnip. Marxism is one perspective on the world, and actually a quite narrow one. There are other social classes beyond the two that the reds point out. I suspect in considering the events of South African apartheid the Marxist class perspective might not be the most useful.

And the ICC definitely resent anarchists.

Lots of information and analysis here:

http://issuu.com/mokonyane/docs/the_big_sellout

http://dialectical-delinquents.com/?page_id=4599

http://dialectical-delinquents.com/articles/class-struggle-histories-2/south-africa-now-then/