Don't give up just yet. Someone with your experience surely deserves an opportunity!
I am in a similar boat. I have a good amount of airline experience between international ramp ops at ORD, approx 3 years of station agent experience with American Eagle and so on.
I found out through a phone call interview for DL ramp a few weeks ago that theirs, and almost all US airline HR is now contracted*!!! Infact, most of them don't even have a CLUE about airline ops!!!!
*- I asked when I called why she said peoplechoice or whatever, over "Delta human resources." Again, they're contracted to do their job for them.
My only suggestion for you, alter your resume to be understandable at a high school level. I know it sounds absolutely degrading, but I keep several resume's of various details ready just incase.
I hope you haven't given up yet!
777ORD