I am having exactly the same problem, as well. US Costumer service is trying to help me via phone (1-800-275-2273). I am on hold now, 42 minutes deep, and glad I charged my phone before attempting the call.
I keep getting "escalated" to higher supervisors, but they have each been very pleasant, and sound earnest in their desire to help find a solution.
Update: While they couldn't find it in the main Apple Technical Support system, a Ms. Brandy (an "Agreement Admin"), was able to pull my serial number up on her independent Agreement area system. They are putting together a kit for me to use to participate in the iPod nano (1st generation) Replacement Program now. Not sure what that means. Will advise soon (I hope).
Solved at 57 minutes!
Apple has provided me a "special" number to present at my local UPS store, who will package and ship the unit to Apple at their expense. All they require me to do is take the iPod (and the unique identifier number) over to the UPS store. The final manager I spoke with, a Ms. Gem, was equally delightful (i.e. eager to please, very approachable, and earnestly apologetic about my time lost on hold while they sought a solution).
In the interest of your time, you might want to suggest (early in the conversation) that they ask an "Agreement Admin" to look up your serial numbers as well... and have a speakerphone and something productive (or fun) to do, on hand, to ease your time spent on hold.
Final note: The pleasant Ms. Gem stated that it takes an hour (or so) for UPS to get the info they need to accept my drop off, and Apple is looking at circa 6 weeks on the arrival of my replacement back on this end.
Excepting the time lost, full marks to Apple for a nice service experience. Grade: A
