Did you check the gearbox forums for a fix? Maybe try joining an online match at a different point in the main story. I was booted after killing Bnk3r but before starting the Angel fight. I was STUCK inside the elevator area. The doors to Bnk3r wouldn't open, but I couldn't open the chamber to Angel either.
Joined a game online further along in the quest and it fixed me just fine. I hope you can get a fix man