Of course not! If there was you would have the lounge agents being asked to swap FF numbers on the way in, before repeating the process on the way out.

How frustrating - there should be a phone number on the desks similar to those that say "How's my driving?" on trucks to report these incidents. We all make mistakes from time to time, but to refuse to back down after being shown evidence - or even to call someone to check when asked - is not acceptable in any front-line customer staff, let alone those paid as well as BA's.