Anyone know how to get my money back for an item mis-sold to me on ebay?

this is a bit long winded but please bear with me. A couple of weeks ago my wife's phone broke and she bought a replacement phone on ebay. The phone was advertised as being on the 3 network and 3g connectivity. When it arrived it wouldn't read her sim card so she took it to the 3 shop to see if her card had been damaged at the same time as her old phone. Her card worked fine in the phones in the shop so they asked to see the one she had bought. They tested it and said it was only a 2g phone that wouldn't work with any modern sim card. We contacted the seller who said it wasn't his fault the phone was old but after much debate agreed to refund the money if we sent the phone back. We sent it recorded delivery but he wasn't home to accept it. When we told him this and that the phone was at the sorting office. To which he replied that he didn't know where that was so would not be collecting it. He then withdrew his "goodwill" offer of a refund and reported my wife to ebay! Claiming that HE was being harassed! All I want it our money back including the postage as I don't see why we should be liable for anything as he mis-sold it to us. We complained to ebay but they just tried to tell us to sort it out with the seller. Any ideas of what else we can do?