Air passengers' rights

If the airline places you in a class lower than that for which the ticket was purchased, it must refund part of the ticket price to you.

The airline must, within seven days, reimburse:

• 30% of the price of the ticket for all flights of 1,500 kilometres or less
• 50% of the price of the ticket if the flight's point of departure and destination are both within the EU and the flight is over 1,500 kilometres in distance (with the exception of flights to/from areas outside Europe that are under a Member State's control, such as the Canary Islands or French Polynesia) or if the destination is outside the EU and the distance is 1,500–3,500 kilometres
• 75% of the price of the ticket for all flights to destinations outside the EU with a distance of over 3,500 kilometres or the destination being e.g. the Canary Islands or French Polynesia.

If the airline places you in a class higher than that for which the ticket was purchased, it may not request any supplementary payment.