Working in a Parliamentary office we regularly get complaints about airlines from constituents. In the case of Ryanair it's often difficult to get through to someone directly.
Sharon Hodgson (Labour MP for Gateshead East) wrote to the Guardian the other day with contact details, which I'm delighted to circulate further:
Caroline Green is Head of Customer Services (sic) and her direct email address is:
email@example.com (Please don't send mindless abuse).
The direct dial number for their head office is +353 1 812 1212
Hope it's useful.