@OPFX (Sorry for the late reply. Life is not being kind to me right now...)
That's odd... I have never been in that situation, but as far as I am aware, removed works are just 'unpublished'. I you cannot find any trace of the song in question in your projects, you should contact an Audio Portal Moderator to inquire what has happened - and perhaps also 'why'.
Yatsufusa
This sounds as if you should fill out the appeal form. IIRC, it is linked to from the message you received.
OPFX
I didn't get a message. Song just disappeared.