I am so sorry to hear that you have become a victim of this scam.
My first suggestion is to write up a detailed summary of what happened to you, including dates and times of conversations with the "roommate" and with all bank employees, then I would go to
http://scamvictimsunited.com/resources_ ... _check.htm
and and contact all of these places with that information.
Next, you have to decide if you want to try and work out a payment plan with the bank, or if you would like to try and fight them with the reason being that they should have caught this (WAMU knows about this scam, and you even said that when you went in with the second check the teller said it might be check fraud . . . why didn't the first teller catch it?)
Please let us know if there is anything we can do to help.