score:6
I just called immigration at OR Tambo airport, and they said that normally you should only be given the remainder of your original 90-day visa-free visit unless having left Africa altogether - this is in order to prevent people from doing visa runs (living in the country without a visa).
However, I've heard anecdotes about land border agents often being very lax and esy to bribe into giving you a few more days if necessary because of your return date.
How long are you actually planning to stay in South Africa? The best way to get a longer stay is not to border hop, but to apply for an extension ASAP through the Department of Home affairs
Upvote:3
I successfully traveled to Mauritius and back, I stayed for 5 days and they gave me a new 90 days, but your first 90 days needs to expire while you're gone, if you return before they expire they will give you the remaining and if you leave after they expire you will be deemed "undesirable" and banned from the country for 1-5 years.