The mother of a 14-year-old boy slammed United Airlines for reportedly instructing the teenager to board the wrong international flight. On Sunday, Anton Berg, of North Carolina, was scheduled to fly from Raleigh to Stockholm via a stop at Newark Liberty International Airport (EWR) in New Jersey.

However, at the Newark airport, the teenager boarded a Eurowings flight headed for Dusseldorf, Germany, rather than the Scandinavian Airlines partner flight he was booked on. The mix-up happened despite the boy's parents, Christer and Brenda Berg, paying United Airlines an additional $150 to escort the teenager to the correct flight, local media WRAL reported.

Anton sent a text message to his parents after he realized he was on the wrong aircraft. The boy's mother said she tried to reach United Airlines by phone but was unable to do so. She also tweeted directly to the airline to inform them about his son.

“He is an unaccompanied minor going to ARN. You probably put another kid in his place who is supposed to go to Germany. The ARN is due to take off any second. The Eurowings to DUS has stopped on the runway. Do something! - call me,” she pleaded to the airline. However, she received no information from the airline for over an hour.

A representative for the airline later reached out to Brenda saying that her son was being rebooked on a different flight to Copenhagen. He arrived in Stockholm on Monday.

"When somebody says unaccompanied minor, wrong airplane, wrong country, everybody should’ve stepped up and done something," Brenda told WRAL, adding that the screw-up was a "cosmic failure" on the airline's part.

Anton had “mistakenly received a boarding pass for the [Eurowings] flight,” which was boarding at a neighboring gate to the Scandinavian Airlines flight," Eurowings said in a statement obtained by Fox News.

“The boarding for both flights was handled by an external service provider who was in charge for both SAS and Eurowings,” the airline told Fox News. “The passenger mistakenly received a boarding pass for the EW flight to DUS instead of a boarding pass for the SAS flight to Stockholm.”

Eurowings added that the crew “reacted immediately and informed the captain” before the plane turned back for the gate at EWR. Anton was handed off to Port Authority and Transportation Security Administration staff.

United Airlines
A United Airlines plane sits on the tarmac at San Francisco International Airport in California on April 18, 2018. Justin Sullivan/Getty Images

United Airlines issued an apology for the incident.

“The safety and well-being of all of our customers is our top priority, and we have been in frequent contact with the young man’s family to confirm his safety and to apologize for this issue,” the airline wrote. “Once Eurowings recognized that he had boarded the wrong aircraft in Newark, the plane returned to the gate — before taking off. Our staff then assisted the young customer to ensure that he boarded the correct rebooked flight later that evening.

“We have confirmed that this young customer safely reached his destination.”