If a post is removed is there not normally a message saying that it has been removed and why?

Yes, a removal notice is posted.

Sometimes posts get caught in "responses to removed" meaning there be nothing wrong but the offending post was quoted.

 

You can always PM the Mod who posted the notice of removal.

 

Sometimes an entire topic may be removed in which case there is nowhere to post a notice.

In that case, contact Support.