Sorry to hear that. Do you know for sure that the bag is gone for ever? Usually it takes a month or so for an airline to decide the bag is really lost.

Until it is really thought to be gone, BA won't compensate you. Even if it is does result in it being lost - and most bags do get reunited with their owners - compensation is limited by international treaty to a certain amount per kilo - this is going to be less than the value of your bag, and as such, you may need to rely on your own insurance to replace the stuff which was inside.

However, if the bags are only misconnecting, you may still get them back - I'm sure you'll breathe a sigh of relief if they do. Have BA been able to tell you where the bag is currently?