Ryanair has reportedly banned customers who were issued a chargeback by their credit cards for flights that were in operation.

A chargeback is when a credit card customer disputes a purchase on their credit card, and is refunded — even if the company does not agree to a refund.

The flights in question were purchased as non-refundable tickets and operated as scheduled during the pandemic. The story was first reported by MoneyFirstReport by customers in a forum. But the airline has since told CNN that the passengers chose not to take the flights because of travel restrictions imposed by governments. Passengers affected have reported it wasn’t just mask mandates or similar rules, but that they were not able to fly because of travel bans at the time.

Ryanair said “fewer than 1,000 people are affected,” according to CNN, and “chose not to travel and then unlawfully processed chargebacks via their credit card company.”

Ryanair did say once the passengers “settle their outstanding debt” they will be un-banned by the airline. Passengers who were refunded by the airline for canceled flights are not in the group of banned customers.