Time waster bidding my listing

[dadsabuilder]

I had a **bleep** who's bidding on my listing then  canceling the bid by  emailing ebay saying  put in wrong amount  then day later bids again then emails Ebay again saying I changed the listing  cancels it again how can I change the listing when i got bid on its locked 

[pixiesen2012]

cancel his bids and put his ID on your blocked bidder list

Cancel a bid

http://offer.ebay.co.uk/ws/eBayISAPI.dll?BidderBlockLogin