They won't accept payment because in their eyes, the account is paid off. Even if they did accept it, it would say "paid CO" which wouldn't help your score any. I'd focus on GWing to get the lates and the settled comment removed.
GWing aside, I have seen a couple of rare posts where the poster successfully paid the difference via a PFD-like arrangement on a settled balance. I recall Chase accepting PFDs in the past, but I don't think this is one of those rarities. IIRC, Amex and Macys was one. I know Chase accepts PFDs too.