It sounds like the old 'game crashes zoning between the main server and instance server and character gets trapped in limbo' bug again. Unfortunatley, this rare issue only tends be fixed when the game goes down for maintenence, where it will automatically kick your character back to your home server (I think there is a time limit for the client to have a character attempt to zone into instance content and which is meant to move them back to their home server if it fails to do so, but sometimes it fails to occur and this issue happens). Submitting a bug report as mentioned above may help also.

I hope you can get this issue fixed quickly either way.