Staff incompetence costs me

I'm waiting in line to check in to my flight to Cape Town, on the 28th of December 2017 at just before 5.30am. Its busy as is to be expected. I get to the check in and im exactly 5 min over the time and the staff explain to me that I'm too late and they just served the last Cape Town passenger. She calls over some guy who says he called loudly for all Cape Town passengers. Absolute nonsense no one went through the line and no one asked me where I was headed. And as stated a passenger on the same flight was just served before me. They do absolutely nothing to help me except to try cover themselves. Your ticket booth then charges me over R900 to get on a flight one hour later. Absolutely garbage behaviour from your staff and the R900 is complete thievery. I will never fly with your *****ed lazy airline again, plenty of other options availible.