It's relatively common in some areas where criminals follow these trucks and take packages left by the delivery service. The criminals know that you might not be home (you gotta work for a living), so they take advantage of the situation. Apparently, this criminal didn't like your shipment. I don't know if FedEx (or others) will allow you to do a will call pickup at the warehouse. Call them an see.
I always had my Fed-Ex packages delivered to where I worked. It's very common for packages left on your doorstep to be stolen.
Sounds like it was left outside your door when it was delivered and someone stole eit, then found they couldn't use it so trashed it.
PICK IT UP AT THE POST OFFICE,,ITS SAFER THAT WAY