Six major airlines have refunded $600 million to passengers affected by canceled or significantly changed flights, and the U.S. Department of Transportation (DOT) is assessing for airlines that delay paying out the refunds, federal officials said Monday.

“When a flight gets canceled, passengers seeking refunds should be paid back promptly. Whenever that doesn’t happen, we will act to hold airlines accountable on behalf of American travelers and get passengers their money back. A flight cancellation is frustrating enough, and you shouldn’t also have to haggle or wait months to get your refund,” said Transportation Secretary Pete Buttigieg in a statement

The U.S. carrier Frontier and five other foreign carriers will pay a combined $7.25 million in civil penalties for “delaying refunds so long that they violated consumer-protection rules,” according to the department.

The other airlines penalized were Air India, TAP Portugal, Aeromexico, El Al and Avianca, with the Denver-based Frontier required to pay $222 million in refunds and a $2.2 million penalty.... Read More: The Hill