Originally Posted by
TheMoops
Sounds like the charge in question would be a "seat selection fee", not an upgrade. Seat selection fees are specifically listed as valid uses of the credit - as long as you stay in the same cabin. If the OP chose a different airline or never bothered to enroll, well then I think they're out of luck on that one...
Depends on what OP meant by "upgrade seats." I agree if it was a fee for a preferred seat, it probably should have been eligible. If it was an upgrade for a different class of service, it was not eligible per the published rules. And if OP used the term "upgrade" in speaking to the AMEX agent then denial would be expected.
As a data point, I recently purchased an upgrade to F on aa.com, and it did not reimburse. Seems to have coded as ticket purchase.