This was definitely an automated ticket. I was not stopped by a police officer.

I called Hertz in South Africa, and a representative was able to tell me that it was a fine of 600ZAR for doing 83km/h in a 60km/h zone. She also gave me the ticket number in a slightly different format, but I am still unable to find it on any of the websites.

The ticket was issued back in December, and I have not received anything in the post from the South African authorities.