I know it is a terrible reflection on FT and our premium snobbery, but I am assuming this was all in business?

If so, I am not even sure why you are making a claim in that situation? Presumably you are not down on TPs since you would have got 40 + 140 with AY, but instead you got 40 +140 with BA. Also if you were rebooked under BA flight numbers you would have got a lot more avios than you would have when booked on AY.