Did you manage to find the contact info for Facebook?
I managed to set the Facebook username for the WRONG Fanpage that I administrate, and I desperatly are trying to get in touch with Facebook to ask them to change it for me.
Sat via Login | Facebook for our Facebook fanpage.
I have tried e-mailiing them at firstname.lastname@example.org, email@example.com and calling them at (650) 5434800.
Add me at magnarmedia @ Skype if you want to help me with this matter.