EBAY Unfair settlement of a dispute with sellers San Jose California

I purchased a book on half.com and I changed by mind because I realized that it is the not the book I wanted and the seller never responded to my request to cancel the order. I got the book and then I sent an e-mail to the seller and they never responded. I contacted half.com which is owned by ebay and e-bay customer service sent me and e-mail approving my return and I sent the book back and I got another e-mail stating that I am not qualified for a refund because I did not get a respond to his e-mail. I sent the book so does that mean that the seller got the book but I don't get a refund? How can they agree to a full refund, plus shipping and return shipping costs and then completely  change their position.

I also bought what I thought was a bulletproof jacket and the advertisement was very deceptive. The advertisement said that the jacket is made of kevlar and is body armour and ballistic. All these terms are associated with bulletproof jackets particularly ballistic. It turns out that the jacket only protects against crudely designed knives and is designed for prison guards to wear so that they won't get stabbed. The seller was a con-artist and he sent me a jacket that was filthy and the label did not even seem to be the original. Why did e-bay side with the seller. It is obvious that the customer service people are competely ignorant about terms like ballistic which mean that jacket can stop bullets.

Patrick

California