I had a situation with Chase were they closed down all my cards and the letters stated many varied (and bogus) reasons. When I called chase and argued each reason with them, they finally admitted that it was none of those reasons and their real concern was my overabundance of credit all together. They said if I close down a nice amount they will reopen my accounts (which of course I did not do).
Point is when you speak to them you may find out whats really bothering them. People do get results sometimes with calling and being persistent. No guaranty it would work, but it's worth a try.
Personally, after my F/R which I passed, I don't play much with my AMEX cards because their too good to lose.