Dallas, TX (KDAF) -- Southwest Airlines, the self-proclaimed "low-cost" carrier, has landed into trouble with the U.S. Department of Transportation.

The DOT fined the airline for what it's calling "unfair and deceptive" competition.

So what brought on this turbulence?

The DOT claims SWA advertised super cheap seats last October — from Atlanta to New York, Los Angeles and Chicago. The price — $59 each way. Just one problem – the aviation agency couldn't find any seats for that fare.

Southwest was slapped with a $200,000 fine for the alleged violation. What's more, the DOT said another "false fare" case was documented in January 2013.

In a statement to NewsFix, Southwest said in part, the television spot that aired the fares, "incorrectly stated three cities that were never intended to be a part of the $59 sale."

When the mistake was noted, Southwest, "pulled all incorrect advertisements off the air."

The airline also added it honored the $59 fare for its customers.

Sounds fine, but the airline must still fork over its fine.