Where do you go to enroll?
They've had this for quite a long time. About two or three years ago I got a letter in the mail with this same offer. I went online to enroll, just for the points since I would never carry a balance, and got an error message. I tried again a couple days later, same error message.
I called and spoke to a CSR and explained the problem. They looked into it and told me the reason I wasn't able to enroll was because I already was. Apparently they took the liberty of enrolling me in it themselves, so no bonus. 
I had gotten into this program as well even though I do not ever plan to use it (though nice to have JUST in case). However, AmEx may have made a slight mistake on the bonus points for me... 
20,000 MR
I had called as I was a little over a month in and nothing yet but was getting close to a Virgin Atlantic transfer offer expiring and needed them to escalate the bonus. A few calls in and they did. However, the manual points request must have been made separately from the original automated request as probably 4 more weeks later, another 10,000 kicked in. I justified it by thinking "I never got a sign-up bonus for my Green card!"
Did the enrollment into extended payments result in a HP for anyone?
