Well so much for the Gold line... I've now had another response to my case basically reinforcing that they thought I got a free upgrade and that I would have to send them proof of a paid upgrade.

Which is nonsense because it was a BAH booking, upgraded over the phone, so I have nothing apart from the fact that final balance of the holiday was higher than when I originally booked.

Perhaps I should go to MCOL for the money I paid to upgrade, as BA clearly doesn't think that I needed to spend it...