Hi I am southern suburbs cape town, and was checking on this topic, ther is an inspection cover on my house where the single phase incoming cable from the street box. is attached. I am Guessing the ground spike is below the cast floor.
In t picture you can clearly see the Neutral Earth Bond at the right the t wires go to the prepaid meter next to the DB board. I Presume the single green wire goes down to the earth/grounding spike.