Have you considered the DOT? I would avoid some of the hyperbole, about discrimination and extortion.. but I think you have a valid complaint. You can click on quick links on this site and it will link you to the DOT where you can file your complaint.
You might also try to complaint to the CAA in Hong Kong, which is a Special Administrative Region of China and so regulates it's own airlines. Try this link..
HK Civil Aviation Authority Complaint Hotline 2867 4318 / 2867 4203
Public Relations Office, 46/F, Queensway Government Offices, 66 Queensway, Hong Kong
Email
enquiry@cad.gov.hk Fax2869 0093