Thanks for the replies. To answer a few questions:
1) Yes we have the claim check showing the other name
2) It was at a kiosk, but with 2 workers assisting her! she said that she was the only one there (It was PHL which is often slow), so she doesn't understand how they may have mixed them up since there was no one else there!
3) SEA was able to send messages to SBA last night, and apparently 1 of the bags is on the way to SEA right now. Whether or not it is our bag or the other person's, we'll find out. it's supposed to arrive in 30 min, and I'll give a call back this afternoon to find out.
Is it possible to ask for a US agent? Do I just tell them I want to escalate the issue?