Sorry to say, but it looks like you've been scammed

Bitcoin has the same irreversible properties as cash, buyer beware. Hopefully it was not too hard a hit for you. Buying high-value items with bitcoin is a little silly since there is no buyer protection. Better to use a "seller-beware" form of payment (pp, cc) unless you are down with goods that fell off the truck, but then you got to trust the buyer. Not recommended without escrow at least!