Use Contact Seller to ask about 'return for refund". If the item is damaged (or otherwise unsaleable) ask if photos would be acceptable.
If return is required, and he is fully within his rights to require that, use a tracked service.
If he is not cooperative go here:
http://resolutioncenter.ebay.ca/
And file an Item Not As Described dispute.
You will be required to return the item with tracking.
If the seller does not refund you on receipt, Paypal will and go after him for their money.
This is the third almost identical question I have answered in less than 10 minutes. EBay should be putting this information in a more accessible location. And I say that as a seller.