Your p.s. is totally inaccurate. Have you ever tried fighting amex for a signup bonus? Its worse than fighting city hall
Bli ayen hara, I always had a rep willing to help with me, whether interest charges or annual fees or some other charge or points issues.
So now when you have a screen shot of the offer which shows 100k and you don't get that offer, why would they not honor it? (yes you could have gotten the screenshot from while the offer was around.)
So now I would suggest you get a rep on the phone and tell them where you see the sign up bonus and let them see for them selves what you see and then go ahead with the signup or have them help you apply and then I'm almost positive you should have no problems!