Appalling service

My daughter had a flight tonight at 20h35. We got to the airport at 20h00 only to be told they won't check her in. The supervisor on duty was very rude and arrogant and said we were 5 minutes late and my daughter will not board the flight. They then proceeded to tell us we need to pay an additional R300 just to change her flight to tomorrow morning and when we went to pay we were charged R750. For reference the board did not show that check in was closed, only make your way to the gate. The service and disrespect we received tonight from Simkelo was absolutely appalling and we will never book with this airline again. Unfortunately I can't give less than 1 star