After every patch in WoW there is major lag and rollbacks, The day patch 3.0.8 came out I purchased a shield with my emblems of heroism, after I purchased it I was disconnected from the server. When I logged back on I had all my emblems and my shield.
If you notice your server lagging and disconnection you alot, spend some of those emblems and hopefully you will receive your item and keep your emblems.