Andy,
My pair did arrive in todays post, but the spare ticket is still subject to my dad receiving his pair of tickets. As he is totally useless when it comes to anything technical like touch tone phones or cash machines. He wasn't sure if he had done everything right with his phone call, so I made one from home just to be sure.
Well my call must have worked as i have my tickets, but as of today, my dad hasn't received any. But theres still time yet.
Fingers crossed that he gets a pair, then i can send you that spare that you are after.