Was gonna ask, have they turned up yet! There's a bibles worth of stamps on the envelope, and the recorded delivery
stickers,so they probably can't see your address.
I'll give you a suggestion,
Hold onto the tickets, they don't have the actual track name or date on them, I believe that they are generic tickets, where they use the same design for all the races, because they came from Dunlop/BTCC, and not from the actual curcuit, so you may be able to use them at a later race
(may need some blagging skills, but its worth a try).
You'll see what I mean when you get them.