Well the first reply I got was that my cards weren't activated (they were the day before), so I had them activate them again. Next try brought the same results, another SM and this time the reply was:
We apologize for any inconvenience this experience may have caused you.
We apologize for the difficulties you've experienced while trying to enter the sweepstakes. Our programmers are working on the issue you reported and we expect to have it resolved soon. Your patience is appreciated.
You can mail your entries to:
2011 Holiday Sweepstakes
PO Box 834
Lombard, IL
60148-08934
This is from their official rules:
1. ELIGIBILITY. The 2011 Citi® Holiday Sweepstakes, (.The Sweepstakes.) is open only to legal residents of the fifty (50) United States and D.C. who are at least eighteen (18) years old at the time of entry and as of October 27, 2011, have a Citi-branded credit card...
It seems to be what they told you is right there in the rules. I still haven't been told this yet by a rep. so I'm going to try to milk it for what it's worth and hopefully come out with some bonus miles. I will update if there is any.