If they're not as described, and you paid on paypal, contact the seller - tell them you'd like a refund. If they don't play ball you can raise a paypal claim, who will more than likely back you up.

The paypal claim should cover your initial P&P charges too - so if the seller wants them back, you can tell him you are happy to return at his expense - it'll need to be a tracked service.

The key thing is that they can't be as described, or shown - so double check the listing and any photos they had up for signs of damage or the brands being different.