Passenger rights: file a complaint
Passengers who believe they have a valid complaint against an airline regarding denied boarding, downgrading, cancellation or long delay to a given flight should first submit such a complaint to the airline operating the flight concerned.
Should the airline fail to provide you with a reply within 6 weeks of receipt or if you are not satisfied with its reply, this form should be sent to the national enforcement body (NEB) in the Member State where the incident took place.
If the incident took place at an airport of departure outside the EU, you may contact the national enforcement body in the Member State of flight destination.
List of competent national enforcement bodies is available in document National Enforcement Bodies underRegulation [EC] 261/2004