Highly recommend Claim Flights service
In my case the whole process lasted more than 2 years, because as I've been informed, the airline wasn't agree with the compensation and it was necessary to go on court, the process being transfered to a local lawyer. In this time, I was periodical informed about case status by Ms.Agnieszka Fanslau and Mr. Kunicki, which were very professional, helpful and responsive. In the end I received the compensation I wasn't even expecting. Highly recommend Claim Flights service!