Good Shepherd, you really are an angry bunny are'nt you! Time of the month perhaps?
Is Caernarfon a licensed aerodrome? If so, contact the relevant department at the CAA (Aerodrome Standards)and tell them whats going on. If it's as bad as everyone is making out, then they should be concerned enough to investigate. Give clear and concise evidence of what is happening, like breaches of the Air Nav order etc, otherwise they will just think its another anti-aeroplane nutter on the phone again.
P.S. I take it the airshow advertised later in the year at Caernarfon is off then?