It looks like we did have a file for this song in your account, which was marked as deleted. I have undeleted the file but also marked it hidden. You should be able to see it both in your C3U file manager, and in the C3DB if you search for the song. If this is the version of the custom you want to release, simply click the “publish” button on the song’s C3DB page and it will be visible to all. If you need to upload a newer version first, look for the song in your file manager, then click “Upload new version” in the Actions menu for the song, then follow the instructions.
I don’t know if this is what happened, but in the future when you want to replace an existing custom with a newer on, don’t delete the old custom first; use the “Upload new version” action instead. Otherwise you could find yourself in this situation again.
Let us know if anything still seems off!