My car cost about 40 & it seemed cheap, but then add on 22 and it becomes very expensive compared to the other "reputable" companies

Save some money and stress and just don't use them

They're based in London and act as a rental car broker. I would not use them. I don't have any experience with them in South Africa but I can't imagine they would be any different by region. Don't use them.

I doubt they will be any better in any country. My experience is they take your money up front and then if the local company they sub contract to add charges, dismiss it as your problem
Read the small print very carefully, I will never deal with this company again