Kulula counter checking closes 1 hour before flight

My son was to return to JHB on flight MN910 at 10h20 the 1st January 2018. He arrived at the checking counter at 9h25 to be informed that checking for that flight was already closed. When he asked why, they said the checking had closed an hour before the time 09h20. The website says 20 minutes before the time and I know that due to it been peak season you have informed travelers that the counter will be closed 40 minutes before the time. So when and how did you inform the travelers that 1st January 2018 they would need to be there an hour before the time for check in?

My son now has to book a ticket at double the price while he has to wait for you to refund him for the other ticket.He was due to start a new job on the 2nd of January 2018 but now will only be back in JHB on the 3rd and start his new job on the 4th. How on earth is this right in anyone's books.