In February I took a flight on Air China. At check-in, I gave the agent my Mileage Plus card, and the Mileage Plus acct. number was printed on my boarding pass.

Somehow, Air China decided to put the miles into my Air China account rather than my Mileage Plus account. They have acknowledged the mistake, but say that there is no guarantee that the miles can be switched to my Mileage Plus account now. United needs to "accept" the miles.

Does anyone know how United would make the determination about whether they can accept the miles and what recourse I might have, either through Air China, Star Alliance, or United, if they do not accept the miles?

thanks