Didnt rad whole thread. But I used to work in the oil industry. I did Petroleum Installations however the company I worked for was an Oil Distributor. And they sold higher octane fuels in 20L drums etc.
So, google for Oil Distributors in your area and give them a call asking if they can supply. Start with BP, Shell, etc. Don't google BP south Africa, that won't help. You are looking for their distributor in your area.