Sellers can't give negative feedback anymore. Ebay has realised that it only needs to focus on the buyers, it doesn't care about the sellers now because as long as ebay has buyers sellers will keep coming no matter how badly they are treated as proven in life people will crawl through **bleep** to make a buck so they can pay their bills.
This also means sellers cannot not do anything to harm buyers including leaving negative feedback anymore.
The only thing you can do is report the item/seller as unpaid, which gives them a strike against their username, if they do it to everyone they get kicked, if they do it occasionally well nothing will happen to them.
