Do UK banks hate money lol? I really hate their stance of 'we don't like transfers' rather than judging the case on it's merits.
It sounds like you explained yourself well enough to your bank manager. Maybe he was unable to explain it as well to his head office. If it was me I would want to speak to them directly but this might not be possible I guess.
I'm at RBS (currently owned by us
) and haven't had problems, but I've not done many bank transfers to other players (probably no more than £2-3k).