In the months the coronavirus outbreak has spread across the world, the Department of Transportation noticed another uptick: an increasing number of Americans being denied their rights to airfare refunds.

"The Department has received a high volume of complaints on air travel matters related to the COVID-19 public health emergency," a DOT spokesperson said in an email. "Many of these complaints concern lack of refunds, assessment of change fees, and inability to reach an airline representative."

Before the coronavirus pandemic took a major toll on travel, the DOT had a rule in place that if an airline cancels a flight, it must provide ticket-holders a cash refund for the airfare and fees. (If a travelers cancel their own tickets, there's no rule or guarantee for a refund.)

But as people were told to stay home to "flatten the curve," travel restrictions were issued and nonessential travel was all but banned, airlines stopped following this DOT regulation, according to the complaints received by the agency and tweets from customers and industry insiders.

On April 3, the DOT issued an enforcement notice to airlines that even during this pandemic, U.S. and foreign airlines must give customers a cash refund if a flight to, within, or from the United States is canceled or has a significant schedule change.

For people still struggling to get a refund, industry experts told us their advice.

  • Call the airline. Travelers who were stonewalled by airlines in recent weeks may have a different result when calling back after that latest DOT enforcement notice.

"Everybody should be able to get their cash refunds," says Charles Leocha, the president and cofounder of the advocacy group Travelers United. "They paid for something. They're not getting it. It's basic American law."

For those who were given a flight credit for a cancellation and would like their money back instead, airlines are also required to honor that request.

"In that [DOT] memo, they said at the end that the airlines should now contact everyone whose arm they twisted into taking credit and inform them that they have their choice," Leocha says. "They can now get cash back, or they can leave the credit in place."

  • Call the airline again. As the saying goes, if at first you don’t succeed, try, try again.

"First, politely say, 'Thank you, appreciate your time.' Hang up. Call again," says Scott Keyes, founder of Scott's Cheap Flights. "The reason why is that airline agents have a lot of discretion about which refunds they process. So oftentimes, it's not as though there's a blanket policy and you'll never get one agent to treat you differently than another."

Keyes says that although you're unlikely to change one agent's mind, you could have better luck with one of the thousands of other agents taking customer calls.

"I can't tell you the number of times and I've been told no on the first call, no on the second call, then yes on the third call," he says.

Make sure to be nice when calling agents. Not only is it a stressful time for everyone right now, but it's also in a caller's best interest.

"I would always be very nice, because if you're a jerk, they put a note in your record," Leocha says.

  • Contact your credit-card company. Keyes says that when all else fails, enlist the help of credit-card companies. Card protections are in place for these very reasons.

Keyes uses this step as a last resort, because the process can be more of a bureaucracy hassle than going to the airline directly.

"Every credit card and bank has a process where you can dispute a charge if you've paid for something and you didn't receive that service," Keyes says. "So if you paid for a flight and the airline canceled the flight, they are not allowed to hold your money hostage.

  • File a complaint with the DOT. Report issues with airlines directly to the DOT through the agency’s website.

"The Department maintains an aviation consumer protection website that provides useful information about passenger rights, including issues related to flight delays, cancellations, and refunds," the DOT spokesperson said. "The website also has an online complaint form so that air travelers can quickly and easily file a complaint with the Department."

Both Leocha and Keyes recommend filing a complaint with the DOT.

"If the airlines refuse to [issue a refund], get the person's name, and get it in writing," Leocha says. "Say, 'Please send me in writing that you refuse.' Then it's very important to complain to the DOT."

Filing a complaint isn't about blowing off steam. It can be good for both the traveler and the entire traveling community.

“The fact that the Department of Transportation put out the directive they did, I think is directly attributable to the hundreds or thousands of complaints that people were filing because the airlines were behaving so poorly,” Keyes says.