So there are a couple of issues here:
Firstly it’s effectively a travel agent booking so SAA won’t deal with the OP directly and secondly, and perhaps most importantly, SAA is grounded, has returned about 75% of its fleet to lessors and all airport locations and call centres are closed.

They are allegedly closed until 31August, but that’s only because they were originally closed until 31 July and didn’t reopen then.

OP needs to be dealing with Chase. Good luck.