I do know that they are illegal without a permit! But i know of many people who keep them and dont have permits,and of petshops (a bit out of my range) that sell them. I have had one that I gave away as a sling because I did not have a permit, and have friends who keep them. I'm not a beginner in keeping tarantulas. Have been doing so for a couple of years now. I have researched them and watched my friend's OBT grow since I gave it to him, have looked after it and fed it countless times, so I know what I'm getting myself into!

It has nothing to with the fact that you are capable of keeping them or not, it has to do with the laws of the country that this site abides by.
As for petshops that sell them or friends that keep them, best would be to report them to the green scorpions. That way we can show nature conservation that we are serious about protecting the countrys fauna and flora and they may make it easier to get permits in the long run.
Do you know the fines that you are getting in to if you get caught with them?

Makes sense. Okay how would I go about obtaining a permit? And could you explain to me why one needs a permit in the first place?

"The OBT's growth rate, sack size and aggresive nature, coupled with the fact that they will survive in our climate, make them a very real threat to our local species. Where they escape/are released they will merely systematically decimate our local baboon spiders."

Okay I've got my answer

You can apply for a permit through Gauteng Nature Conservation.
They are illegal because Pterinochilus is one of the genera that are protected in the country from over collecting and trade.
To find out which genera are protected, read the rules section.
For more info, use the search function here on the site and search for 'permit'.
Happy reading.