Do you have any specific reason to use SA's program? AFAIK it's not a particularly good program.
At any rate I think if you are based in Switzerland you can get M&M credit cards, a Diners with BA, or a Flying Blue Mastercard. AMEX would not transfer points to SA.
What are you trying to achieve exactly? Earning some M&M points and then redeeming for ZRH-JNB would probably be reasonably easy.