Needed to change a ticket on CO, and at the time I wasn't enrolled with an airline, so I figured I'd give it a shot and went ahead and signed myself up for CO/UA. I called in and managed to change my ticket an hour later (hold times
athough at least they called me back). The change fee of $142 (100 euros) posted separately from the increased fare, and it was completely credited back within 2 days ^.