No problem. I have the model numbers memorized since I check iFixit's website daily to see if the OEM white backplates for the 4S are in stock. They sent you a GSM iPhone 4 part, which won't work on a 4S. I'm glad they are replacing it for you.The Steve Jobs backplate I received from an eBay vendor in China turned out to be for the 4, not the 4S. I emailed them and they said they'd send out the right one.
I'd like to thank Mindi for figuring out that it was the wrong piece.