FedEx lost my package?!?

I ordered a $200.00 phone with a 2 year contract through Verizon, and paid 80$ for overnight priority shipping through FedEx last night. Today, FedEx showed up and I was stoked. When I opened it, I saw there was a bunch of pharmaceutical stuff inside, but no phone. I looked at the receipt paper and I received someone else's stuff, but my name/address and tracking # were on the box. How can this happen? I called FedEx and they're going to pick this stuff up tomorrow, and agree'd to refund the shipping costs, but have no idea where my phone is. What can I do?