A family from San Jose was billed $13,470 by T-Mobile for using the internet for a half-hour while on a flight.
Vivian Chung and her family, including son Nicholas, traveled to Vietnam for a family reunion.
They returned to the U.S. in great moods ... that is until they got the T-Mobile bill.
The Chungs believed they had protected themselves from roaming and internet charges by keeping their devices on airplane mode during the trip, but something went wrong.
They had been charged over $13,000 for using internet on Nicholas' iPhone.
Nicholas said that he used his phone to play games during a flight, but they were offline games that didn't require internet.
The family estimates that he played for roughly 30 minutes.
T-Mobile tried to help the family by reducing the bill to $3,8000, but that was still too much.
When ABC7, who originally reported this story, looked into the games Nicholas was playing, reporters found that quite a few mobile apps use data even when they don't need internet to run.
That is likely was happened to the Chungs.
ABC7 spoke to T-Mobile and eventually got the charges dropped all together.