I had two PC seat charges for last year (at $17.99 a pop) that didn't credit. I spoke to AMEX a couple of days ago and after some pushback they agreed to credit them. They tried to argue that they were upgrades. I disputed that and simply said they were seat assignment charges. They were happy with that and so the credits appeared today. My challenge is also that there's very little I can use the credits on. I am BAEC Gold so pretty much everything would be covered by status. It really is only PC seats or F&B in coach - and it's not that often that I fly coach.