From today Wed 19 October 2016, South African Airways is said to have banned Samsung Note 7 from all its flight. This is a blanket cover ban whether its hand held baggage or cargo. This is after airlines in US banned Note 7 as well and its now a criminal offense in American to carry a Note 7 on-board.
In trying to prop up its image, Samsung set up exchange boots at few selected airports to exchange Note 7 before people fly to US thereby saving them a criminal offense and heavy fine from US.
Im not sure if this offer will be extended to SAA, but since the SA government is not involved and have not setup any fine for fliers, l do not think Samsung will extend this offer to SA
So just to be sure, leave your Note 7 before you try to fly to SA with SAA.