When I began using my SPG card I had the same situation, however, the charges were not "declined" but the code was that the merchant needed to call in for authorization. Once the merchant calls then everything was OK.

When, in my opinion that was NOT OK, as I have been a member for 17 years, and have made multiple 30-50,000 charges on my Platinum without a hitch. When the third merchant received the "Call In" message, I got on the phone and told the rep that I would be cancelling all of my accounts immediately if they did not flag that I am a long-time member and that they easily had access to my spending and payments habits, regardless of which of their OWN cards I was holding. It is NOT out of the CSR's hands as that is her job, so don't accept that answer. If she personally doesn't have the authority to do it go to her boss.

I never had an issue after that time, even using the card internationally.