If you think your monthly phone bill is exorbitantly high, just be happy that you didn't get dinged for $13,000 for using the internet.

Vivian Chung and her family were visiting relatives in Vietnam recently. Before they left San Jose, they all set their phones to "Airplane Mode" to avoid roaming and internet charges. Or so they thought.

When they returned home, the family was greeted by a T-Mobile bill to the tune of $13,470. Apparently the iPhone belonging to Vivian's son, Nicholas, had accessed the internet sometime during the trip. Their best guess is that it happened as their flight was coming into Vietnam, over a period of about 30 minutes.

Nicholas insists that he never used the internet and had left his phone in "Airplane Mode" for that exact reason.

After reaching out to T-Mobile, the bill was dropped to $3,800 which they thought was still unfair. The family contacted 7 On Your Side and the local news station got the company to drop the charges altogether.