I recently arrived at my destination without my checked luggage. Carrier A cheked it through to my final destination with my final Carrier B. It didn't make a connection in LHR (surprise) although I did (several hours, due to a cancelled flight). Because of my travel schedule, it took two full days before I was reunited with my suitcase.

I have filed a claim with Carrier A for an emergency clothing purchase. Should this be filed with Carrier A or Carrier B?