peacha: just lie, say you got them as a gift from your granny then start to complain loudly in the shop. its their fault they dont police the fakes so will swap
Bad form! It's your own stinking fault if you tried to cheap out by going on eBay and you ended up with exactly what you paid for: cheap defective products. If you didn't buy original A8s from an authentic source you deserve what you got; why should the dealers pay for your mistake?
B&O does what they can to squelch the fakers, but it's hard across international lines, and in an environment like eBay where someone's identity is easily obfuscated. When you have a luxury brand known for quality and design, whether it's B&O, Mont Blanc, Rolex, and so on, there will always be some loser trying to copy you to make a fast buck.