My last post was about as rant-y as it ever gets around here. But it worked. I received a response from Amy at Performance customer service within mere hours. The answers:
1. Yes, they have the part.
2. Yes they will send me one.
3. No, they will not charge me for it. Amy says they don't charge for "small parts" as long as they are being ordered by the person who originally bought the bike or frame (I have a feeling this is what "small parts order" means in Performance-land).
4. They were able to look up my original order for the frame, that is how they found me in their system.
In conclusion, if you order a frame or bike from Performance and find yourself in my position, your best bet would be to contact them and reference the order number they have on file from when you bought the bike. Better yet, ask them to throw in a spare when you buy the bike- I bet they'd do it on request. If you don't do that and all else fails, get yourself a blog with tens of readers and complain on there, and tell customer service that you're doing it.
I should close by saying that while this was a pain, I'll still use Performance. I enjoy my Scattante very much- I find it to be a light nimble commuter and someday I might even pop the fenders off and race it a bit. Online retailers often offer great deals and that can mean valuable savings for people who like to work on their own bikes.