FWIW when I've had a discrepancy in the Avios that were credited to my account, the response I got made no sense but I decided it was not worth pursuing it further. My impression was that CS just wanted me to go away and all the replies were in that direction, rather than trying to truly understand what happened or fix anything. In all fairness, I don't think they are empowered to do much, and I sense it's a systemic thing rather than individual CS reps.