The mother of a boy taken off a plane at Gatwick due to a lack of seats is demanding EasyJet overhaul its ticketing process.
Casper Read, 15, was travelling alone to grandparents in France when he was asked to leave the plane after a man was allocated the same seat.
Stephanie Portal, from Worthing, West Sussex, said her son felt "he had been kicked off and cheated".
EasyJet has apologised, offered compensation and is investigating.
"There was him and an adult for one seat and the adult was getting very angry about it all," Miss Portal said.
"I don't know if it was a random selection, or if they thought Casper would be the easier option to get off the plane, but it's wrong.
"He was asked to go to the cockpit - thinking he would be allocated another seat - but before he knew it, was taken outside the plane and told to go to the information desk.
"He was left to make his own way through the airport, nobody in departures to meet or help him, and despite there being three more flights that day was put on the latest one and had a 10 hour wait."
Miss Portal said a manager at EasyJet told her the airline overbooks its flights by up to five seats due to people often not showing up, and that it was the last people to check-in, not the last to buy their tickets, who were in danger of not getting a seat.
"The whole system needs an overhaul and the attitude of the attendants was irresponsible," she said.
"Children should never be pulled off a flight and the people who are should be given priority on the next one.
"Airlines cannot gamble on the probability of people not turning up."
'Procedure not followed'
"Casper is quite laid back but he really felt he had been kicked off and cheated," she added.
A spokesman for the airline said: "EasyJet is sorry that Casper Read's flight from London Gatwick to Toulouse was overbooked on 20 July.
"We are investigating why he was able to board the aircraft as he should have been informed at the gate.
"EasyJet has a procedure to protect unaccompanied minors but unfortunately this was not followed on this occasion."