OP are you traveling with children under 18 years of age ? If so this may be the issue and BA wanna check you have all the document required for Home Affiars ( South African immigration ) to grant you entry into South Africa. New requirements, introduced by the South African Department of Home Affairs from 1 June 2015, specify that all minors (children under 18 years) are required to produce, in addition to their passport, an Unabridged Birth Certificate which shows the details of both parents for all international travel to and from South Africa. Further documentation may be required. Trust me all airlines are on the ball when it comes to checking these documents before allowing you to travel to SA.