I am so sorry this happened but we are aware of this and looking into it. I appreciate any continued reports of this, and if possible when reporting this, can you let me know what Mount / Skin / etc. you are seeing as locked so I can make sure they all get restored properly.
I also want to confirm that these items are not “removed” from your account, but by the actions of a bug, locked from use. You should regain access to these items without any problem once the issue has been resolved.
Again, thank you so much for the reports, keep them coming, and I apologize for this inconvenience!