Phones are forbidden when you have cool and overly elaborate magical means of communication. Everyone knows that.
If nothing else, it would have made sense to ask Pandora why she was there prior to trying to kick her out. Imagine if it had worked.
"She's gone! VICTORY IS MINE! And I have no idea why she was here in the first place! Or if she'll come back! Or if maybe her intentions were as noble as I believe mine! Or... Huh."