Welcome to Flyertalk and welcome to the BA forum. It does indeed sound like a really bad Christmas and I'm sorry to see that is what brought you to this forum. You can post up to 5 times in the first 24 hours, a once off restriction.

Assuming we use the rates from 28 December 2024, the limits is £1595 approximately, but it is per person, not per bag. Anything beyond this is for your insurance company. After 21 days it's important to claim for a full loss, though BA will continue to deliver for certainly 6 weeks, and maybe 8 weeks.

The overwhelming advice I give here is "do not try to force baggage through the system, it's almost always is a waste of time, energy and emotions". In the run up to Christmas there were thousands of bags delayed, and it's just futile to think that anyone is going to hunt for your bag, it's just a process and at some point your bags will get processed. You just have to keep WorldTracer updated, buy or rent what you need and claim afterwards. Then get on with your life. So long as you are reasonable, BA will pay the costs, and anything over £1595 is over to your insurance company. If you think that BA or a BA agent showed neglect or a wrong failure or omission, this limit can go higher, but you better talk to a solicitor about this since I don't know of any individual who has managed to tackle that on their own.