NEW YORK (AP) — An airfare deal that was, in fact, too good to be true is providing the first test of a government rule prohibiting airlines from raising the price after a ticket is purchased.

On Sunday, hundreds of fliers were able to book a flight to Hong Kong on United Airlines for just 4 frequent flier miles and $33 in taxes thanks to a computer glitch. A business class seat for a flight on United to Hong Kong goes for about $8,500 or 120,000 frequent flier miles.

United eventually pulled the plug and announced it wasn't honoring tickets already sold. People could get a refund without paying a penalty or have the proper amount of miles deducted.

Several people who booked tickets complained to the Department of Transportation, which is investigating.