Unfortunatly the shipping to return it for a refund will probably make returning the item for a refund impractical.
However the process is explained here.
What to do if you don't receive an item or it doesn't match the seller's description
http://pages.ebay.ca/help/buy/item-not-received.html
The best way to shut bad sellers down or get them to clean up there act is by leaving appropiate feedback.
http://pages.ebay.ca/help/feedback/questions/leave.html