Could you describe in more detail what you mean by "mailing address?" You used that term several times, and in the above case, in addition to saying that the address was inputted wrong, you say it wasn't listed as a mailing address. So, was it listed as some other kind of address on your account? What would that be? Or, is the main address on the account where they'd send statements and replacement cards something other than what you are calling a "mailing address?" I'm having a hard time making sense of what you're trying to communicate.

Here's something that happened to me years ago, which may or may not be related to what you're talking about: I had a need to order mail order items to be shipped to an address other than the one on file with Amex where statements and replacement cards got sent, and charges would sometimes fail if the merchant was strict with address verification. I had heard that you could add secondary addresses to your account that would also validate with address verification. I called to have that done on my account, and a friendly rep took down my alternate address and added it to my account. I still had sporadic authorization failures due to address mismatch, so I called Amex again and they confirmed that the alternate address was on my account. I still had failures, so I called Amex once again, only to find out that what had previously been done was to just add the additional address as a "note" on my account, such that a human reviewing my account would see it, but not such that any automated address verification would pick up. I gave up at that point, and still don't know if there's even a concept of having additional addresses on file that will pass automated address verification.