SAA is not sold by many OTAs like Expedia because the entity is basically insolvent and is surviving only on government handouts.

Airlink and flySafair are operationally world-class. They consistently deliver 95%+ on-time performance and 99%+ reliability. These are unheard of numbers in a wider global context. If you book to fly with them, you can pretty much be assured that you will travel per schedule.