Originally Posted by
FlightDetective
You wouldn't happen to check if there is Avios availability on one of the Qatar Airways services from London Gatwick to Doha on the same day?
If there is, you could cancel your BA Avios flight for the small penalty fee, get your Avios back and then buy a flight with Avios on Qatar Airways instead. Qatar will check your baggage through. Just a suggestion, it may not be feasible and also there may be no availability.
Indeed, worth checking. Also note that in the opposite direction, if OP has the same routing in reverse from Bangkok, Qatar will check through to BA on separate tickets so that's fine.
As it stands for the outbound, OP either needs to go hand baggage only or rebook.