Never had a problem with ebuyer (apart from citylink who cant decide whether my house exists or not)
had my fair share of returns with them too, got a couple of memory sticks waiting to go back right now (they failed after 9 months)
I generally detail the fault finding I have done to save them having to work though it with me.
I have done work with a similar retailer to ebuyer and worked on their tech support line, Best one I had was a customer wanting to return a brand new PC
they had gone for top of the line on everything for the machine aroud £7k (built to order) and a few of us had looked at the machine when it was built simply because it really was top notch.
customer was on the phone swearing at everyone that "this f*****g machine is no good, it won't f*****g turn on, you will refund my f*****g money right now" etc etc
eventually I calmed him down enough to work out he was pressing the reset button instead of the power switch.