Sorry to hear OP’s experience. I am glad OP has received the full credit.

i have flown Air China averaging 50K BIS each year for the past 10 years and credit them to my UA account. I only have one missing credit in ten years.

i read some of the posts in this thread and feel some of the assertions and representations made about Air China may not be consistent with my own experience, and want to share my experience to ensure the views expressed here are more balanced.

I have several unpleasant experience with Air China in other areas that I wish I don’t fly Air China as often, but none relate to crediting activities to M+ account.