You file for unpaid item thru the resolution center - customer support, top right of page. You can do that after 4 days of non-payment. Then you wait another 4 days and if they still haven't paid, you close the case. They get a strike on their record and can't leave feedback. If they get 2 or more strikes on their record they will be blocked from
buying by many seller's and they could even be suspended by ebay. After the case is closed you will be refunded your fees and then you can relist or offer a second chance. And put the buyer on your blocked
bidder's list - site map, bottom of page, middle column, near the top.
What to do when a buyer doesn't pay (unpaid item process)
http://pages.ebay.com/help/sell/unpaid-items.html
Of course, if the buyer does end up paying before the 8 days is up, you will then be obligated to ship the item.
bidded - (v. nonstandard)
Simple past tense and past participle of bid -
(Wiktionary)