I just flew SEA-YVR-KIX (all AC) // KIX-HKG-BKK (all CX) on an AC J-class fare. The paper ticket (required because of CX segments) was issued by AC in YUL, and they apparently neglected to put the ticket number in the PNR. Therefore, CX simply cancelled my PNR, and this ultimately resulted in an involuntary downgrade on the KIX-HKG segment as J was completely full. (Lucky for me I was even able to get on the plane, they told me....)

The PNR printout CX gave me reads:

*THIS PNR WAS ENTIRELY CANCELLED*
...
SSR OTHS AC HX/CANCELLED DUE TO TKTL EXPRD X
SSR ADTK AC ADV TKT NBR TO CX BY 04AUG OR SUBJECT OT CANCEL
...



CX, of course, declines all responsibility, stating that "my travel agent" made the mistake. They were quite firm, to the point of being almost rude, about this.

Where do I even begin to complain, and to whom?

What would be "reasonable" compensation for such a downgrade?

(I will be the first to admit, as people here can easily figure out, that the entire ticket cost less than either of the three long segments would have in full J, but if AC decides to price its J fare for SEA-BKK at US$1429, then I suppose that's not of my concern! It is the reason, of course, that I flew this route as part of a < $5k almost all J RTW I am on.)

Any comments / suggestions would be most welcome. I suppose it's an unusual situation given the two carriers involved.