I have a similar question. I'm flying a KLM (KL 622) flight next week from ATL-AMS that I booked through Delta. My flight shows up on delta.com, but I couldn't change my seat. I went over to klm.com and could make seat selections on their site. I selected an Economy Comfort seat and while deciding whether to pay for it or not, my session expired. When I logged back in, it has me sitting in the Economy Comfort seat, (10J) but I never paid the extra fee for it. Air France's site (I'm connecting with them) shows me in 10J as well. Delta still has me in my original seat, 33C.

So my question - Where am I sitting? Did I get an Economy Comfort seat for free (or will this be corrected at some point)?