The airline is not responsible for incidents beyond their reasonable control. Strike action is beyond their reasonable control. However, they still have a duty of care which doesn’t extend to financial compensation but does extend to looking after you and I refunding you are rerouting you back home..
You already mentioned Bott and co who have listed here what you are entitled to and which you have probably already seen.
Using the list of criteria, and any receipts that you have, you can take the airline to the Small Claims Court.
You need to write to them telling them that unless they pay you the list of expenses under regulation 261, you will if you Small Claims Court proceedings without further notice.
You can easily if you Small Claims Court proceedings online here www.moneyclaim.gov.uk
If for any reason you lose (which I cannot see), the worst that can happen is that you lose your court costs that you may have to pay a tiny amount of solicitors costs to Ryanair if they use solicitors. Probably no more than a hundred pounds at most.
Can I clarify anything else for you?
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