I, too, have had my ability to purchase amex cards destroyed.
I bought 5,000$ worth via BC with my SPG card. This triggered a financial review wherein I was told that if I ever bought amex GCs again with my amex credit cards I would have those credit cards closed.
Which is amazing considering the site prefers you use your amex CCs to make the purchase -- preselecting them.
So I went on trying to make purchases with a Chase visa and was not successful once -- I've been getting the same errors that you guys have. Many, many calls to their abysmal customer service have brought me to the edge of declaring jihad on all of India. I've never had such a terrible customer service experience. No one knows why my orders don't go through, many promised callbacks that never occur. I can only suspect that I've been secretly flagged as a 'do not sell!' by Amex's nazi GC department.
To make matters worse, I purchased premium shipping on the last order that came through. When I attempted to cancel and have the premium shipping refunded (since none of my orders were going through....) all of the customer service people were convinced that I was on a free trial. Trying to get a refund for this was a herculean task. I was finally promised one, though, after two weeks, my card has not been refunded..
I've heard only good things about american express. I've experienced only bad. Their financial review team is akin to the spanish inquisition and their gift card site is horribly broken and secretly bans you. Not to mention the customer service is manned by idiots.
I could go on and on and on. The stress and anger these people have caused isn't worth any amount of cashback or points/miles.