Bad service

My flight was at 13:35 today I arrived at 12:50 the lady at the help desk told me I was late tried to explain what happened but she could not listen to me and told me had to pay 1650 for a stand by flight. I did not have a choice but to pay that money because had to attend my friend wedding while standing at the line where we need to get our bus to take us to the plane a white man came running and when I asked him why his such in a hurry he told me his 30 minute late for the flight. But he was let inside, So what I wanna know is that how you treat your clients by the skin color cos I was 10 min late for my flight and didn't know had to be an hour late as it was not stated.. and d white man was like 45 minute late for his flight and was let in ... I'm really disappointed as I was told that Mango has the best service ever but got a terrible service. Will like a feedback from you as I was treated very bad and had to use my last cent for something that could be fixed and what irritated me the most is that the flight was delayed but got to understand that but my reason wasn't considereted