There are two reasons why your thread was locked:

Either
1) Your stuff is in a location you haven't bothered to check yet (Calamity Salvager, THe armoire in your inn room, or on a retainer)

-or-

2) if you're certain you have checked those things, then this is an account issue and you need to contact SE support over this. Calm down, and post a polite, detailed ticket and they will be able to work with you.

"logging a complaint" won't solve your issue or get them to not lock a thread that isn't where it belongs. You need to be polite and civil and they will be happy to help you through the appropriate channels.