Have you tried pushing it back into place? The bumper is held in place with a few plastic tabs and has quite a bit of play. you should be able to position it back into place. It's hard to tell from your photo exactly how badly its dislocated.
I've had my rear bumper off (long story). It's hard to tell what is going on in your pictures, I can't tell what part is separating. Along the side of the car, the bumper has tabs that fit into slots on the rear fender. The body colored part has tabs heat that are heat welded to the black part of the bumper. If that is loose, the bumper needs to be removed and a hot screwdriver used to melt the tabs to bond the two parts of the bumper together. If you take a better picture from the side of the car rather than from above, maybe I can see what is wrong and help you. Again, I have taken my bumper off and heat welded the tabs and replaced the assembly and it looks like new.
I thought from the first photos that you had a rear bumper issue. I would guess the front is attached the same as the rear. If you can't get it pop back in by forcefully pushing it, the tabs might be broken. Sounds like it's time for the dealer to look at it. Let us know what it was. Good luck
Vette is dead on you most likely have a busted clip or locator pin. Skip the dealer go to any decent body shop. Dealer will not repair anything, they only replace parts. if it is a clip or pin they can have from their supplier same day in most cases. If the bumper is damaged at that point they have all sort of repair tricks to fix a hidden tear and you will never know the difference.