Oh forgot to ask... when you use the vouchers are you given change?
I was told by one of the coffee shops in T4 (near the Terraces Lounge) that they would not give me change for my £10 voucher. I though this was odd as I really didn't want to buy 3 sandwiches, 2 drinks, 2 crips and some pastry! I didn't want the coffee shop whose food was already over-priced to rob me/BA. I would have preferred to spend the vouchers as I desired.