I agree with Andrew! The picture on the listing shows the split bottom case which was only on the A1278 2008 model.
See it here:
MacBook Unibody Model A1278のアクセスドアの交換
Contact the seller first and then eBay for your buyer protection program. You did not get what you paid for. But the seller may not have known either.
The listing is for a MD322LL/A which is a :
Apple MacBook Pro "Core i7" 2.4 15" Late 2011 Specs
Identifiers: Late 2011 15" - MD322LL/A - MacBookPro8,2 - A1286 - 2563*
to confirm, look on the back for the serial number, then input it here:
Now take the bottom off and look at where the RAM goes in, the serial number should also be there and match the bottom case.