Mango airlines refusal because of expired drivers

SHOCKING REALLY Shocking... My brother had to come from pe to O. R Thambo on the 8.8.2019.....to our shock he gets there and the flight is delayed by 3 hours then they say to him he is not allowed to fly cause his drivers license have expired by 29 July... They literally refused him to get on the flight.... I'm shocked to my bones because of mango my family cannot be with us because of an expired driver's license of a week old.