Complaints against airlines surged by an astounding 5,500% last year with 83% of those complaints relating to refunds for unused travel. Meanwhile, in recent months, the Federal Aviation Administration (FAA) has proposed a series of fines against unruly passengers mentioned in complaints from airlines themselves.

Last year, as the pandemic cut air travel by 96%, airlines received billions of dollars in federal taxpayer money to help them stay afloat.

"That was given by taxpayers, not once, not twice, but three times, without any givebacks to consumers," Bill McGee, longtime consumer advocate and aviation adviser with Consumer Reports told National Public Radio.

According to McGee, airlines are currently sitting on up to $15 billion in refunds that are owed to customers.

"I will tell you that I have never seen a single issue generate so much consumer anger," McGee said. "It's off the charts and this has been going on now for 14 months."

However, Airlines for America, an industry group with seven member airlines, has reported that its members have already refunded $13 billion to customers last year, equal to 20% of operating revenue according to an airline spokeswoman quoted by NPR. On top of those refunds, airlines reportedly issued billions of dollars worth of travel credits.

Those travel credits might actually be part of the problem. Many airlines chose to issue vouchers rather than refunds, but customers are now discovering that their vouchers are approaching their expiration dates.

"Those vouchers are absolutely coming due right now," travel editor at The Points Guy travel website told NPR.

To help address this issue, Senator Richard Blumenthal, D-Conn., and Senator Edward Markey, D-Mass., say they will propose legislation to force airlines to both offer cash refunds in exchange for vouchers and do away with expiration dates on the vouchers that are given.

Still, customer anger isn't restricted to their homes and social media. The FAA said that they've received 1,300 airline complaints regarding unruly and disruptive passengers in 2021. In recent weeks, the agency has proposed civil penalties against more than a dozen passengers. Some of those fines exceed $30,000.

For ignoring mask orders and coughing and blowing his nose on an airline blanket, one man faces a $10,500 fine. For slamming overhead bins and shouting profanities at airline employees before being escorted off of the flight by law enforcement, another man is facing a $9,000 fine.

Just this January, the FAA announced a new policy under which the agency would no longer offer warnings or counsel to disruptive passengers but would instead go straight to the enforcement phase.

Meanwhile, U.S. airlines has issued their own bans against 3,000 passengers who refused to follow their mask guidelines.

Perhaps ironically, a survey of airline passengers taken last year showed airline customer satisfaction at a record high.