apparently late for checking in, gives paid seats

I were five minutes late for checking in, when they tell me the flight that i booked and paid 2 weeks prior to travelling date, are full! Then they tell me there are no flights available for the rest of the day..... I can wait and hope someone doesn't show up and take their place and still pay R1359.99 for that seat, ten minutes before he flight depart! Whit ch means i still had time to get on that flight before it was sold to someone else.<br> They want your contact dertails when you make an internet booking, but they dont use it to find out if there is any problems. So i went to another airline and had to pay R1851.52 plus the ticket with mango, so a flight from durban to Johannesburg cost me R2579.24 becose they dont care about there customers..... And now they refuse to refund me!!!