CIM - The merchant does not accept this type of credit card

[smcleod]

I've verified that our Payment Gateway accepts the following: Visa, MasterCard, American Express, Discover...

However I still get this error message when running an Amex transaction: "The merchant does not accept this type of credit card"

How do i resolve this issue? Thanks in advance!

[RaynorC1emen7]

Doesn't sound like a programming issue, call support.