COMPLAINTS PROCEDURE FOR APPLE

Hi I have a had an Ipod for just over a year amd have had numerous problems all of which I hasve received little or no help from Apple. I have posted the pronlems on here and despite some peoples best efforts the Ipod is still broken
Now I paid close to 300$US for this product so as you can imagine I´m pretty vexed. I would like to know does anyone know the complaints procedure for Apple?
I would like the vent my anger!
Thanks
Mark