The regulars here can save you the trouble and send you the response you'll get from BA. It is an automated cut-and-paste job that includes the assuaging phrases "we know you're disappointed" and "understand that you feel let down on this occasion." It will also tell you that "the safety of our passengers is our utmost concern" and that they "appreciate your loyalty as a [insert tier here] member of our Executive Club." Ultimately, though, you'll be told to pound sand, since "you were on a separate reservation that had nothing to do with BA."