So after a week of trying I got through to online chat. I found the secret is to keep typing
speak to agent until you eventually get put into a queue and counted down from 10th to actually getting to an operator.
Once I got through it took a painful 55 minutes for them to collect my details (3-4 minute pause in between each ask and then lots of other pauses). I was then told that a request had been raised and I’d hear in 7-10 days (who knows whether or not miles and tier points will now actually post).
As for the other people in my booking I was then told that each one would have to contact BA directly themselves (even though 2 of them are children) and all exec club numbers are in the system. So that’s going to be another 4 hours of pain