Without any further information at my fingertips I would place the blame on AMS; When I was travelling AMS-LHR and the flight got cancelled we had to get our baggage back and re-check onto another flight, just one small problem........ they had even managed to lose the bag before we actually went anywhere!
Anyhow, more power to your elbow for remaining so calm about it all - in my (quite considerable) experience of lost/mislayed luggage most airlines seem to do their utmost to p!ss everyone off, rather than trying to make amends. (KLM even had the cheek to tell me that they were no worse than everyone else in such circumstances!)
Glad you're sorted now.....