I bet when you "delete" something facebook (and many others) just marks it as "hidden" so you will think it is gone.

The same happen to me but with yahoo, I had an old account that was long unused, because I didn't want to lose any contact that could happen I redirected it to another email, then, after a couple of years, I decided to delete the account because only spams were being redirected. A year later I notice that emails started to come from this "deleted" account again and so I tried to login and for my surprise it was active.

So don't expect to "delete" anything, and I think we shouldn't expect to have our rights respected, these companies provide a service that is not really for us.