I’ve got a similar, but also different query

I had DOH-BKK in F booked with Avios for travel in March. Been swapped to 777 so downgraded to J. I’ve accepted the downgrade but QR are saying no refund of the difference in Avios until after travel - which is still 6 months away. I think this is absolute madness. Anyone else has this situation and been able to get QR to see sense? Or is there any other recourse?

thanks