The conciliation service ECRCS: European Car Rental Conciliation Service is based in the UK and can arbitrate in cases where car rental problems have occurred. The company must be a member. Participating companies (as of June 2022): Europcar, enterprise, AVIS, Budget, Maggiore, Hertz, Thrifty, dollar, Alamo, National, Firefly, Sixt.
It is possible to contact the ADR body in all EU languages, but you will always receive a reply in English.
You can submit the complaint only online and in English.