What a dispointment from FlySafair

I booked unaccomponied minor flight ticket for my child through FlySafair. They sent me the payment information and I paid for everything. The departure date came and when I got to to the check-in point I am told that the booking is incorrect and that I need to pay an additional R750 for the flight or I need to go back home with my child. What a disappointment and didnt have R750 lying aroung to pay for a TICKET that I already paid for.