I just sent an e-mail to applestoreinfo@apple.com stating that I did not get offered AppleCare+ (I didn't receive an e-mail asking if I would like it added either) and that I would like it added to my order, and in less than 45 minutes it was added. So if you are having issues calling in and getting it added, give the e-mail address a try.
Thank-you kindly!
I did the same, and within a minute it showed up as "processing" so I assume it'll be fine. I was hesitant to spend the money on this at first. That was until yesterday when my 3GS got ripped out from its car mount. Said person also dropped her own phone on the driveway a few minutes later.