Please. You're stuck on the headline.... which sounds about as sensational as a DOT seeking to look good to low-information voters would want it to be.
This is a non-event.
Nobody typically cares about the accounting details, but hey, I'll dive into that rabbit hole for you.
F9 appears to have already paid that $222M back to customers already after the DOT started haranguing them over their policies. Depending on how Frontier accrues for earned revenue (actually flown/used tickets) vs. unearned revenue (future ticket sales), that $222M was never actually recognized as income/revenue and held in reserve or escrow. It wouldn't have necessarily been reflected in their cashflow or their cash equivalents because it was still a liability.
The fine is because they jacked people around before DOT started knocking at the door over a year ago. DOT is highlighting the $2.2M fine, but even that's been overblown. DOT is giving $1.2M of that back to F9 because they proved they'd also issued refunds to customers who made voluntary changes.
So.... ultimately it sounds like a $1.2M penalty. That's a rounding error when it comes to their available cash.
Put otherwise, it's 3-5 hours of ticket sales for a day. They're bringing in somewhere around $6M a day right now.
Now... if that $222M is incremental i.e. refunds they denied and now have to pay out, that's going to be a different tune.
I seriously doubt that only because of the $1M credit DOT gave them for their voluntary efforts. If there was another $222M in liability to be refunded, they'd have never offered a credit offset from the original fine, and the fine would be much, much larger based on past practice.