Mango flight controllers chase their customers away!!

I had a flight yesterday morning on mango from O.R Tambo to Cape Town, departing joburg at 05:55. I still have my computicket slip as proof of this because i booked my flight at the money market counter at checkers. I got to the airport at 04:40. An hour and 15 minutes before my flight was scheduled to leave. Now, according to my knowledge, check in opens 40 minutes prior to departure and boarding gates close 15 minutes prior to departure. I was clearly on time. There was a line of about 20 people infront of me and the flight controller came up to me and casually let me know that the person standing infront of me was the last person that she was going to be allowed to check in and she is cutting the line there. I asked if i could make use of the self service check in because i had no baggage to check in, just hand luggage, and she told me no, I need to get space on another flight. After trying to reason with this woman, I realized that my efforts were futile. I decided to call my dad and have him come and help me. While waiting for my dad, a guy came, it was now 05:40. This guy was late! He spoke to the flight controller, she made a call first, had one of the other people print his boarding pass, and off he went. How freaking unfair!! I then had to go to the FlySafair counter and spend R1500 of my savings on a plane ticket to come back home. I wasted R850 on a mango flight that the flight controller wouldn't let me even check in for, even though I was on time, just because she felt like cutting the line!! I am disgusted. I am a frequent flyer, at least once a month and mango was always my airline of choice but after yesterday, I will never ever fly mango again and I will encourage everyone I know to never fly mango because a belligerent flight controller might cut the line and not allow them to board the flight for no reason. I am infuriated with Mango!! Their service is the pits!!