OMG, are you my husband?
I'm having the same problem, except Air China says we didn't take the flight, either. "No record" of me on several flights? In these days of added security, etc.? (Got nothing to do with class; anyway, even economy should be getting the miles; the excuse being given here is "we have no record of your butt being in our seats).
The UA person got incredibly rude with me; just kept repeating the same sentence over and over, to my increasing frustration.
Beginning to see a trend here...