This is a topic which gets raised weekly on the forums. The button was removed around two years ago, as sellers where using the threat of Negative feedback to intimidate buyers. You need to open an unpaid item dispute against the buyer and ebay will refund all of your fees once case is concluded in your favour. ( you can close the case in four days ) . The buyer will recieve a strike on his account which can affect his ability to purchase from other people in future. You can go to site map ( toolbar at the bottom of every page ) and look for Preferences. Click on this and set your blocked buyer preferences to buyers with two or more unpaid strikes in 3 months ( or whatever other combination you prefer ). This will prevent repeat non payers from being able to bid on your items. You can also add his id to your blocked buyer list.