You have free delivery on your listing and I imagine its going to be quite expensive to send. Did you intend using free delivery? It would be more normal to just have buyer collection on there.
If you want to send it you can use:
http://www.shiply.com
If the postage thing was a mistake you could cancel the transaction via the dropdown menu for the item on your orders page. Use the reason "Something wrong with buyer's address", ie. too far away to collect. If they've paid the refund will be issued in the process.
And put their ID on your blocked bidder list:
https://www.ebay.co.uk/bmgt/BuyerBlock
