I found out how to send an email to the CEO of Delta (
richard.anderson@delta.com - it's on the How To web site) and sent him an email, after Delta had entirely stopped responding to my emails. I got a VERY polite letter from someone in his office, but that was more than a week ago, and the check has not been forthcoming.
I think it's very important to write in a very polite, businesslike, and concise way when you send an email or letter to the top of an organization, so they don't think you're a crank.
Good luck to all of us uncompensated people!