Get what he said in writing, on his company's letterhead, with a company officer's signature, because there is nothing in AppleCare that says Apple will fix it if they can't repair it after three tries! As far as the pixel issue, have him show you Apple's official documentation on what Apple covers; it varies by screen size and model. Also get in writing his company's policy that they cover any/all dead pixels. Then go to another store to buy your iMac, because he won't give you any of these documents.