As soon as either buyer or seller ask eBay to step in and help, the case is immediately closed in the buyers favour, with a full refund and they get to keep the item. Are you sure it came out of eBay's money and not yours? Did you check PayPal to make sure? If they've left you feedback, I'd be replying to it mentioning what they've done and naming them so others can see who they are and what they've done. (e.g <username> broke item then claimed a full refund saying it was faulty. Shoplifter.)