The GA said that they couldn't give me a seat on Delta because Delta would not accept a "miles" ticket from another alliance. I am a UA 1K...but I'm sure that doesn't mean anything to Delta.
With my bad luck today, it was a UX flight from PDX...but I don't know whether that has anything to do with their inability to get me a Delta seat.
I just got off the phone with 1K desk too. They basically said the same thing. Offered to give me some good will compensation...20% or 250 Ecert or 10K miles.
I am calling again to see if I can get on a later Air China flight from LAX...at least that's *A so maybe.....