You should claim the money you are legally entitled to under regulation EU261/2004
Was your flight delayed? How much compensation you are entitled to depends on the following criteria:
• for all flights of 1,500 kilometres or less: EUR 250 (± 199 GBP);
• for all intra-community flights of more than 1,500 kilometres and for all other flights between 1,500 and 3,500 kilometres: EUR 400 (± 320 GBP);
• for all other flights that do not fall under (A) or (B): EUR 600 (± 480 GBP).
If the airline offered the passenger a re-routing, they are allowed to reduce the amount of compensation with 50%. To which flights does this apply?
• the flight distance was less than 1,500 kilometres and the flight was delayed in arrival by more than two hours;
• the scheduled arrival of the original booked flight was exceeded by three hours, for all intra-Community flights of more than 1,500 kilometres and for all flights between 1,500 and 3,500 kilometres;
• the scheduled arrival time of the originally booked flight was exceeded by four hours, for all flights that do not fall under (a) or (b).
More info:
http://flight-delayed.co.uk/flight-delayed/