WASHINGTON (NEXSTAR) — Federal officials are taking a closer look at Southwest Airlines after its holiday travel mess. Meanwhile, many travelers are waiting for their refunds from the airline. 

Thousands of travelers were left stuck during the Southwest Airlines meltdown over the holidays. John Erickson was one of them. 

“I was stranded in Denver for three days over the holidays,” Erickson said. 

After several weeks of trying to get in touch with the airline, he eventually reached Southwest and was told he would get a $3,000 refund, but it would take a while.

“Saying it’s going to take months for us to get back what we owe you, that actually is a big problem and frankly I’m glad to see that the Department of Transportation is investigating,” Erickson said. 

He also filed a complaint with the DOT. Secretary Pete Buttigieg wants passengers like him to know the department has their back. 

“We will follow up on every single one of those thousands of complaints, to make sure people get taken care of,” Buttigieg said. 

This week, the agency launched an investigation into whether Southwest made unrealistic flight schedules, which could be a violation of federal law. 

“We’re going to be looking at everything from how flights are scheduled to how passengers are taken care of so we can make sure those airlines are doing right by passengers,” Buttigieg said. 

If necessary, Buttigieg says the department will use tools like penalties and fines to hold Southwest accountable. 

“The point is to make sure that airlines do the right thing to begin with, but we can’t simply lean back and trust that that’s going to happen on its own. That’s why we’re here,” Buttigieg said. 

Travelers like Erickson will be watching closely to make sure they follow through. 

“We need to actually have those promises met by the federal government, because how are we supposed to have faith that we can get from one place to another safely and soundly?” Erickson asked.