(CBS) — They came to the United States for medical treatment for their son, but a French family is now stranded in Chicago because the airline that brought them here won’t take them back.

CBS 2’s Derrick Blakley has the story of this foreign family’s travel troubles.

22-year-old Kevin Chenais weighs 500 pounds and spent a year-and-a-half at the Mayo Clinic for treatment of a hormone disorder.

He was supposed to fly home to France on British Airways, but for seven days, he and his family have been stranded in Chicago.

“We blame British Airways because now they just leave us, and they brought us here,” said Christina Chenais, Kevin’s mother.

When it was time to go back, British Airways essentially decided, Kevin was too large to fit on board.

“If they could bring him here with that problem in economy, there was a way to take him back by economy but just get him back home for his medical treatments to continue,” said Christina Chenais.

In a statement, a British Airways spokesperson said: “Our customer service team worked diligently to find a solution…Unfortunately, it is not possible to safely accommodate the customer on any of our aircraft…”

Kevin requires round-the-clock oxygen and full time medical attention.

“I’m sure a lot of big people like or bigger cannot travel because they have the same problem,” said Kevin Chenais.

They are now out of cash and marooned at an airport hotel and the family now plans to travel by train to New York and board the Queen Mary II to England, all taking time and money they can’t afford.

Kevin’s parents insist British Airways was informed about Kevin’s size and medical needs before they bought their tickets.

British Airways won’t comment specifically on that, only saying the needs of individual customers must be addressed on a case-by-case basis.