To be fair, I have had both UPS and Fedex deliver amps I ordered from Guitar Center to completely the wrong address. More than once I have walked around my neighborhood (frantically, sometimes in the middle of the night after getting home from work, even though the package required a signature they just drop it anyway without caring) looking for a big obvious box laying on someone else's doorstep. Luckily I have been able to recover each one, but I could easily see someone taking the box inside and going wow, I can pawn this! and I'd never know any better.
It is suspicious that you didn't get a response quicker. Maybe I'm naive but I try to give people the benefit of the doubt, and I'd be more likely to trust a fellow gearhead over Fedex which notoriously sucks ass (as evidenced by another thread only a page or so back filled with people sharing shipping related horror stories).
Either way, hope it works out and that it's just some miscommunication.