RealBlackStuff wrote:Get in touch with seller, and put in a claim at eBay and PayPal. Escalate as soon as possible.
If you paid with credit card, you can probably do a charge-back.
In that order, too.
I've only ever had three problematic auctions, all of which were solved quickly and without any loss using the following method:
1) Take pictures. As soon as you receive the item, take pictures of everything, including the unpacking process. (I'm lazy, so I usually only do this for items costing > 100 USD, but it's still a good idea.)
2) Contact the seller. Explain the problem and ask them to fix it (full/partial refund, replacement on their dime, etc. as you see fit.)
3) If their response is *anything* other than "you're right, my mistake, a replacement/refund has been dispatched" (or similar), open a dispute with eBay.
4) Escalate the dispute with eBay/PayPal as soon and as high as possible until the seller has made things right.
5) If all else fails, and if you paid via CC, do a charge-back. Note: this will probably have negative consequences to your PayPal account (PayPal *really* hates users who issue chargebacks), so you might want to make sure that you don't have anything in your account that you can't afford to lose access to.
I've only once gotten past #3 (the first step is invaluable if you have to refute the old "it wasn't like that when I shipped it" line.) I've never gotten past #4 -- few sellers are masochistic enough to want an unsettled claim on their eBay account.
Good luck!