FLYSAFAIR Unreasonable amount for a name change

I booked two return tickets from Johannesburg to Durban - well in advance for the Comrades weekend - due to the covid uncer*****y and it being a very popular weekend. All tickets were booked in my name as I wasn't sure who the other person would be accompanying me to the Comrades marathon. Flysafair is asking R600 to make a name change, I did the name change myself. Seats has been reserved and paid in full. Only a name change well in advance of the flight date - end of Aug.