I called Apple last week. they said they received the phone but that it was being declined. they would not tell me why, but usually it's because of poor condition of the phone. They couldn't tell me more than that. I do suspect it was stolen and they received an empty box because the condition was perfect. I still have not received any official email or had the package sent back, which they said would happen because it was still 'pending'. I don't know why they can't tell you on the phone what the reason for them declining the trade-in is.
Mine also went to Carlisle, PA.
I've been a Mac user since 2002. I have bought every new iPhone since 2007, including lining up at the store for the first one. We've been doing the trade in program for a few years. I hope all of this counts for something.