First step:
You must give the company a warning that you wist to persue your calm, and that should they reject your formal, and time limed request for satisfaction, you will persue the matter thru the UK small claims court.
(Beware the possible problem that RY are not a UK company, and outside the remit of the UK system, however if you find a UK subsiduary, that would be a good start.)
Then go on line for the UK on line small clams procedure, fill in the forms, and pay the sum.
Even RY dont like too much publicity, in the courts, as it might just trigger a class action, and then they are totally fluked.
Print out all E Mail and other communitions.
good luck