This is a followup to my previous question: Flight from EU rescheduled 2 days prior to departure. Am I entitled for EC261?
We have booked a FlyOne Armenia flight 3F 928 from Paris (CDG) to Yerevan. It was originally scheduled to depart at 16:50 on Aug 19, and arrive at 23:10. However, on Aug 17 at 10:39 (Paris time) I received an email that the flight has been rescheduled to depart at 20:00, and arrive at 02:20 the next day.
After the flight I tried to contact the airline for the EC261 compensation, but they outright refused it saying that we are not entitled to the compensation because we took the flight (which is not an excuse, as far as I understand).
Following the answers in the previos question, on Sep 8 I filed a complaint with French Civil Aviation Directorate. I've got an automatic response that my complaint was received, but nothing else has happened for 1.5 months.
What other actions are available to me? I'm not an EU resident, so I can not go to an EU court (or anyway this would be too difficult). I see that there are many websites saying that they will get the compensation for me; how reliable and realistic is this approach?