The U.S. Department of Transportation (USDOT) has punished six airlines by $622 million in refunds to passengers and imposed a $7.5 million penalty.

According to Reuters, this is the strict enforcement of consumer protection laws whereby the hundreds of thousands of passengers who have had their flights cancelled or significantly changed can be rewarded.

"The [USDOT] should not take enforcement action in getting airlines to pay the amounts they are obligated to pay," Transportation Secretary Pete Buttigieg told reporters.

Many of the refunds involved delayed or canceled flights during the covid-19 pandemic, and many travelers waited months or even years for refunds.

Frontier Airlines was required to pay $222 million in refunds and will pay a $2.2 million penalty. Air India, owned by the Tata Group, will pay $121.5 million in required refunds and a $1.4 million penalty.

State-owned TAP Portugal will issue $126.5 million in required refunds and pay a penalty of $1.1 million. Colombian Avianca will issue $76.8 million in required repayments and pay a penalty of $750,000.

El Al Israel Airlines will issue $61.9 million in required refunds and pay a $900,000 penalty. And finally, Mexican airline Aeromexico will pay $13.6 million in required refunds and a $900,000 penalty.

AS Carriers explained themselves to USDOT the reasons for flight delays and cancellations, many concerning covid-19. Portugal's TAP said it faced "an avalanche of refund requests and its call center was quickly overwhelmed."

USDOT awarded the airlines some payments for non-refundable tickets against penalties: Frontier received a credit of $1.2 million, TAP Portugal $550,000, El Al $450,000, and Avianca $375,000.