Originally Posted by The Saint

Your comment shows that you know very little about BA and, indeed, airlines in general. The quote is standard (and would be issued by any airline). The policy is to fly people in the class for which they have paid. However, when operational reasons require, BA (like any other airline) will u/g passengers to fill the flight. Those who benefit from the u/gs are the subject of very many threads here. For obvious reasons, they don't hand out u/gs on the telephone.