Yes, follow it up. I had £150 worth of aftershaves stolen from my suitcase on a journey TXL-LHR-GLA (where also my bag ended up in NCE for some reason...

). I complained to BA about the stolen items and I was reimbursed for the cash cost to repurchase the 2 bottles.
You trust your luggage to BA to (a) keep it safe and secure and (b) deliver it on time at your airport of arrival. In your case (and mine) BA failed on both of these points.