A family were forced to sit on the floor of an airplane during their flight home from Menorca after being told that their allocated seats did not exist.
Paula Taylor, 44, her husband Ian, 55, and their daughter Brooke, 10, from Alcester, Warwickshire, arrived early at Mahon airport in June last year for their flight with TUI airlines.
They were given the seat numbers 41 D, E and F, but when they boarded the plane they could not find their seats and cabin crew instead offered them flip-up 'jump' seats tucked into the crew station, the Daily Telegraph UK reports.
They were later forced to the floor because flight attendants needed access to food and duty free items.
"We made sure we were three hours early at the airport to check in early just to make sure we got seats together," Taylor explained to BBC One's Rip-Off Britain: Holidays.
"We went straight to the front and we were very excited by the fact we had managed to sit together."
Yet, on the plane, they could not locate the seats stated on their boarding passes.
"We all just looked at each other as if to say 'where's our seats gone?' There are no seats where our seats should be," Taylor said.
Members of the cabin crew proposed that ten-year-old Brooke could take the last spare seat on the flight, and Paula and her husband Ian could sit in two spare flip-up chairs meant for the crew.
However, after the plane had taken off, the couple were told that they had to vacate their seats as the attendants needed access to the food and duty free items, which were stored behind them.
On the floor they were joined by their daughter and later the co-pilot of the aircraft, who thanked the family for their "co-operation and understanding".
"He said that how calm we were and he was so grateful because he would have had to, he would have missed the time slot take off," Taylor said.
She said of the floor: "It's hard and it's uncomfortable and it's just filthy. It's just not an experience I ever want to repeat."
The Civil Aviation Authority, the body that regulates airlines in the UK, is now investigating the incident. It has asked TUI airlines to explain why the family was allowed to sit on the floor and is looking into a possible breach of regulations.
Passengers are allowed to sit in crew seats under certain conditions, but must not be left unseated during any stage of the flight.
After being contacted by the programme, TUI offered the family a full £1300 (NZ$2500) refund, blaming the incident on a "last minute aircraft change".
However, Taylor said she "got short shrift" from the airline when she personally complained immediately after the incident, despite having photographs of what had happened.
She alleges that, after explaining to the company that the seats were "physically missing", she was told that there was no record of the incident and offered a "good will gesture" of £30. Frustrated, she contacted Rip-Off Britain.
A spokesman for TUI said: "We are sorry to hear about Taylor and his family's experience with us.
"Unfortunately a last minute aircraft change meant that the seats the family was originally assigned were unavailable as the alternative aircraft had a different seating configuration.
"We're also sorry for the way the situation was initially handled and we'll be investigating this. We will also be contacting the customers directly to apologise and will be offering a full refund."