OK, so I am hoping you didn't ask for compensation for the downgrade, since that's the correct answer in a sense: there is no compensation for downgrades. Instead there is a reimbursement mechanism - either a straight difference or the Mennens formula as shown in the WIki. What is more it is the Refunds team, in the UK, that handles this, whereas I suspect this answer came from an offshore unit with a poor understanding of what they should be doing. Sometimes BA like to argue that Mennens doesn't apply due to passengers agreeing to downgrade, but they seem to have stopped doing that. I'll just repeat my usual advice that when downgraded it is best to ask that your PNR is amended to include the comment that the passenger reluctantly accepts the downgrade under protest. They probably won't do so, but that doesn't matter so much: because you have said that, it removes BA's ability to claim it was something you chose/ Unfortunately the Refunds team never talks directly to customers, but they will talk to the Contact Centres. So ring the Contact Centre and ask them to submit a refund using the Mennens formula.