There are suggestions that SAA doesn't make money on its London routes because of serious over staffing of its London office for political reasons and the number of free seats it has to give away to people connected to the government.
Basically another Air India/Kuwait Airways/Air Zimbabwe i.e. a feeding trough for politicians topped up with tax payer money. Jobs for the boys who can't be sacked, free first class travel and as many over priced contracts to supply as they can get away with.