Got this reply via BBB from Alaska...

"...
I can assure you that we do not sell things that do not exist. As our agent advised you, there was a schedule change for your flight which necessitated a downgrade. The difference in miles has been redeposited and a customer service gesture of 2,500 miles was also deposited into your account. Unfortunately, no additional compensation is due.
......"

They try to blame Hainan Airlines for schedule changes that is not true by all means. I replied to ask for details of this "change"...... Very disappointed.