Originally Posted by
jrkmsp
Searched for availability via Delta.com and then, once I found it, I called until I got an agent who could figure it out.
Yes. It took me two calls: the first was a nice young guy who said it wasn't possible to upgrade and I didn't argue. I then called back and got an older woman who instantaneously gave me the feeling that she was the one who could help me out... and she did. Follow the instructions above and don't be afraid to call a few times until you get the right person.