Good Evening Seatman
Ridiculous. The listing quite clearly states collection only. Your buyer didn't read the auction details properly,or chose to ignore them. What you may have done is to forget to exclude any buyer who lives outside of the UK . For future reference be sure to do this (if you just want to sell to UK buyers) and add to your description that this sale is restricted to UK buyers only.
As the ever sensible CC has indicated cancel the sale quoting problem with the buyers address.
The joys of selling, it's unfortunate that you have run into problems on your first sale.
Good luck and don't let this put you off.