Alexrey, I grew up in Central Africa but I couldn't join the RAF whilst domiciled, I physically had to come to London to live (I then applied via a local RAF Careers Information Office - that was back in 1971). It's how you choose to interpret 'UK Resident Less Than 3 Years' that is causing you to continuously challenge - clearly, you cannot apply to join the RAF while resident in South Africa, simples.
S4G