I always get WP and BA Miles - on dozens of transactions over the years. They are totally separate things. Every shop at BAA airports has to award you WP on all purchases, full stop. If they don't (and once or twice I've had clueless Travelex staff who wouldn't/couldn't) you just scan the receipt and send it to WP later. In contrast to how BAA run their airports, they seem to run WP CS very efficiently ^ 99% of the time Travelex staff correctly swipe both cards.