Returning on amazon

I recently bought a used motherboard on amazon in "like new" condition. When I received it, the board was severely damage and was missing pieces that it was supposed to come with it, I would blame the damage on shipping but the CPU socket protector was in the socket backwards *face palm*. So I tried to return it but the seller was rude and refused to accept it so I had to file a claim with amazon. So my question was how does it work? How long can I expect it to take to receive my money back?