I learned this the hard way. No luggage, airlines blame heathrow, and heathrow has no communcation channel, I think my only option is break in and try to find it myself. How you manage to get yours?
Often the biggest impediment to getting lost luggage back is finding out where in the airport it actually is.
... Turns out, they move "military looking" (lol, pelican) boxes to a separate spot instead of running them on the carousel. I'd have had it in minutes if I remembered to check the tag first.
Have considered its a tastier looking target for thieves, but esp in Asia they seem to have no idea what it is at all.
I hit up 2 Apple Stores and a few authorized resellers in my area and everyone was out of stock. I ordered mine online and it still took a few weeks to get it.
(This is also how airport lounge abuse is done.)