Delta Air Lines was sued by passengers who complained that the carrier refused to offer full refunds after delaying or cancelling their flights in the wake of last month's massive computer outage.

The proposed class action was made public on Wednesday in Atlanta federal court, after the July 19 outage disrupted airlines, banks, hospitals and emergency lines.

Passengers accused Delta of breach of contract for failing to provide automatic refunds, and providing partial refunds only if they signed waivers against pursuing further legal claims.

They also said Delta should compensate them for the cost and inconvenience of rebooking with other airlines, hotels and food, and from being separated from their luggage.

One of the four plaintiffs, John Brennan of Florida, said he and his wife missed a $10,000 anniversary cruise after being stranded in Atlanta on a layover, but Delta offered just $219.45 in compensation.

The lawsuit said the airline's "unfair, unlawful, and unconscionable practices resulted in Delta unjustly enriching itself at the expense of its customers."

Delta declined to comment on the lawsuit, but has said passengers whose travel was disrupted can request and receive refunds, and seek compensation for incidental costs.

Delta's passengers remained stranded, waiting in lines for days trying to get to their destinations," Joseph Sauder, a lawyer for the plaintiffs, said in an email. "When our clients sought refunds, Delta again failed to deliver."

The outage stemmed from a flawed software update from the cybersecurity company CrowdStrike that crashed more than 8 million computers worldwide and affected many Microsoft customers.

Disruptions subsided the next day for many U.S. carriers but persisted at Delta, leading to more than 6,000 cancellations.

CrowdStrike, Microsoft and Delta have since argued publicly over who is to blame and should pay the bills.

Delta Chief Executive Ed Bastian estimated on July 31 that the outage cost his Atlanta-based carrier about $500 million.

Passengers filed a separate class action against CrowdStrike on Monday, also seeking damages.

The Austin, Texas-based company has said it was neither grossly negligent nor at fault for Delta's problems.

The case is Bajra et al v Delta Air Lines, U.S. District Court, Northern District of Georgia, No. 24-03477.