Item disappeared

Hello, yesterday I bought new waist for frost emblem. Today I saw, that my gear score is low again and my new waist disappeared. How can I get my frost emblems back or my new waist? My old waist is Braid of Salt and Fire and new one was Belt of Omission. Please help me I think it was lag after I log out.

I dont know where to write for this problem, but please help me.
For first time i see that kind of item disappeare.

Looking forward for your answer asap :)

Double check your bags and bank. If it can't be found, it's lost to nether.