I had this problem months ago and now it happened again. I deleted a note accidentally and there is no simple way to find the trash if you don't know where to look.
I remembered it was easy to find online, but in the months I didn't connect they changed the UI to make it hard to find online too.
So in case you have the same problem, login online, from the homepage ( https://www.evernote.com/Home.action ) click the 2nd green icon from the bottom (left bar) named "notebooks". To your surprise (or at least mine) there lies the trash. The trash is one of your notebooks. No, it does not make sense to me.
I'm trying to attach an image to make it easier to find.
hope this helps,