Cannot book flight for minor

I booked a flight back from Durban to Johannesburg for my 9 year old son for this Sunday (20 August 2017). He is starting school on Wednesday and I need to get him back from Holiday.

Booking any airline does not allow you to make a booking for a minor unless it is accompanied by an adult ticket. You book an adult ticket and then call the airline and change the ticket to the minor. This is the case with all airlines. They also link this to another ref with the adult the child travels with.

This morning I called Kulula to do change the name to my Son. They inform me now that they cannot do this because I booked the ticket via Vitality (On their website).

I am now out of pocket for more than R1000 rands and have no way to get my son back other than to drive to Durbs and back.

Other airlines have no problem with this (this is how I got him to Durban).

Frustrated that they cannot do a simple change to get my boy back - all other airlines can do this!