Dado que é um voo europeu, O Regulamento da UE 261/2004 é relevante e abrange as suas opções.
Além dos regulamentos completos (relacionados acima), há um resumo sobre Wikipédia que abrange sua situação.
Em suma, como o vôo está a mais de duas semanas de distância, você não recebe nenhuma compensação. No entanto, o Atrícula 8 da EU 261/2004 explicitamente indica quais opções a companhia aérea tem a lhe dar neste caso. Especificamente:
Right to reimbursement or re-routing
Where reference is made to this Article, passengers shall be offered the choice between: (a) — reimbursement within seven days, by the means provided for in Article 7(3), of the full cost of the ticket at the price at which it was bought, for the part or parts of the journey not made, and for the part or parts already made if the flight is no longer serving any purpose in relation to the passenger's original travel plan, together with, when relevant, — a return flight to the first point of departure, at the earliest opportunity; (b) re-routing, under comparable transport conditions, to their final destination at the earliest opportunity; or (c) re-routing, under comparable transport conditions, to their final destination at a later date at the passenger's convenience, subject to availability of seats.
Paragraph 1(a) shall also apply to passengers whose flights form part of a package, except for the right to reimbursement where such right arises under Directive 90/314/EEC.
When, in the case where a town, city or region is served by several airports, an operating air carrier offers a passenger a flight to an airport alternative to that for which the booking was made, the operating air carrier shall bear the cost of transferring the passenger from that alternative airport either to that for which the booking was made, or to another close-by destination agreed with the passenger.
A companhia aérea estará muito ciente dessas condições (e provavelmente estará violando outras seções do código se elas não o tiverem avisado sobre sua existência e de que isso é relevante), então se você as achar não cooperativas, então você deve fazer um pouco mais do que mencionar que está ciente de seus direitos sob a EU261 e eles provavelmente mudarão suas respostas muito rapidamente!