Obsolete computer

Enter man in black leather jacket.
"My brother bought a computer here a couple of weeks before Christmas and he's had nothing but trouble with it. Cost him £300."
"I presume it's a second user computer we're talking about?"
"Yes. £300 he paid. I could have built him one for less. I've already had to put a new power suppy unit in it."
"Well, actually, we only had two second user computers before Christmas and neither of them was £300. Also we refurbish our second user computer before we offer them for sale."
"Well, he paid £300 for it and it's obsolete. You should see the memory board!"
"We have not sold any computers for months for £300. We only had two for sale in the last four months."
"Look, I know he's too late to have his money back but I thought maybe you could do something for him. I know people in the computer business sometimes sell rubbish but I think you should do something about this one."
"We have not sold anyone a computer for £300 and furthermore, we do not sell rubbish."
"Well this computer is obsolete."
"We don't sell obsolete computers."
"You must have sold this one. I've got it in the car."
"No, we don't sell obsolete computers. I will not accept that."
"I've got it in the car...."
(Turns on his heel and makes a sharp exit from the shop........
never to be seen again!
Could it possibly have suddenly dawned on him that maybe he had the wrong shop?