At this point I seriously doubt ryanair will risk a court case they will lose, especially because the law system of any country but Ireland would slap them hard.
There is no need to be patronising and insulting to the Irish law system. Your own country's court system is no shining beacon of light. The reality is that they wouldn't win in Ireland either. Neither would they risk a court case because it would highlight their dubious practices.
Either write back and tell them to get lost or ignore them. The only reason they're bothering to pursue it all is because they don't want everyone walking out at a moment's notice.
I very much doubt your the first to do this and you won't be the last.