After spending some more time in Fourways Mall where I went to watch a movie and bought a couple of books, I left Rockey's and their unhelpful staff to the airport around 15:30, I stayed a couple of hours at the airport waiting for my cousin Stephanie to show up around 18:00. We only saw each other for about 2 minutes since she had to hurry.
I just had the time to give her a big parcel where was packed all the woodcarving bought from Zambia and Zimbabwe: a big bushmen about 1m high, 2 masks and 2 small statues in ebony. I would say it was about 10+kg. I also gave her 3 CDs full of all pictures taken since the Seychelles.
I then rolled the dices and called another backpacker for a pickup: A Place To Stay, first impression is that it is a nice place, gym, sauna, jacuzzi, etc etc... staff is also way more friendly and does not have the Rockey attitude. Will see that in daylight in the next days.
I will probably stay a couple of days in JNB as I have loads of information to assimilate about this place.