AMEX charge off

hello, i set up an agreement back in may 2008 to pay off my amex green card over 12 months. i have not missed any payments but the card did go past 180 days due and it is now showing up as a "charge off/collection" on my credit report. this is extremely frustrating because they promised me it wouldn't be reported negatively, and now it is. my question is: after i completely pay off this amount will their credit bureau department REMOVE the charge off from my account or will they just mark it as "paid in full" - there is a big difference. i called AMEX and they even saw a note in my account that i was told the account would not be reported, but they said they cant do anything and that i have to call this credit bureau dept once its paid off to see what they will do...just wondering if anyone has any idea of what will happen.

thanks