Here's what has happened concerning my internation reservations:

After three months of being on a waitlist that doesn't exist (because CO informed me that there are no waitlists on the CO/VS code-share flights), and after three months of agents insisting that my fare is not-upgradeable (because they ignored the rules that is was ... which they would always realize after having me on hold) I finally realized that it is just not worth it to fly CO. Customer Care was wonderful, and actually authorized a one way refund, as my return is on UA, and as I already have upgrades.