This is what Ryanair has to do when they cancel a flight. Notice the difference in
bold. They can still get away with it if they say the flight is cancelled for reasons beyond Ryanair's control. But an airline would never lie to its customers.
Flight cancellations and schedule changes
* If your flight is cancelled or before the date of travel, is rescheduled so as to depart more than three hours before or after the original departure time then you will be entitled to a travel credit or full refund of all monies paid if the alternative flight/s offered are not suitable to you and you do not travel.
* Ryanair does not provide monetary compensation under Article 7 of EU Regulation 261/2004 for flights which are delayed or cancelled for reasons beyond Ryanair’s control (extraordinary circumstances). You may therefore wish to ensure that you have suitable private insurance cover in force to cover such eventualities.
Your rights under EU Regulation 261/2004 are unaffected, so in the case of denied boarding, flight cancellation or a delay in excess of two hours you will be provided with a written notice setting out the rules for compensation and assistance in line with such Regulation.
* Passengers who book well in advance should re-check their outward/return flight timings on
www.ryanair.com or with a Ryanair reservations centre between 24 and 72 hours prior to departure.