I actually did take digital photos because the signing was ridiculous in the car park. Basically there was three islands, one side had a fence and the signs were down low (I didn't see any of those cos cars were parked in front of them!
: ) and on the outer island, the signs were on gigantic poles above eye sight height (from a car). On the middle island, where I parked, there was a single sign right down on end of the row, next to a bush.. and it was tiny!
So I'm feeling a bit jipped. If I had a visible sign, I had no problems parking properly.
I'm thinking now I'll write a nice letter, then if that fails, ask if the ticket is invalid.
Pity is, I think you can only appeal in writing once.