Comcast Xfinity / FedEx iPhone Scam

I am a victim of a scheme that is well-documented online. After my iPhone was delivered, I was contacted on the same day by someone representing themselves as being with Xfinity and was told I received the wrong phone and that I needed to leave it on the porch to be picked up. They knew every detail, including what I ordered and where / when it was delivered. I never activated or even unboxed the phone. Two days later, someone in a FedEx uniform (witnessed by my neighbor) picked the package up. I called Xfinity the following day to find out when the new phone would be shipped to me. That is when Xfinity explained I had likely been scammed. I immediately filed a police report and submitted it to Xfinity on Monday morning of this week. I received a decision today (Tuesday) from Xfinity stating I am liable since I released the package to a third party. While it is true someone picked the package up while I was at work, it should be acknowledged I was being deceived by someone posing as an Xfinity representative (I do have one voicemail stored from that representative as proof). My new phone plan that covers stolen phones excludes phones that haven't been activated, while FedEx states its liability ends once the package is delivered (Interestingly, the delivery detail says I signed for it, although I was at work).

Although this appears to be a FedEx scheme, how many occurrences will Xfinity allow its clients to experience like this before reexamining their relationship with FedEx? At what point does Xfinity decide to protect its clients, including from its business partners like FedEx?

Currently, I am set to owe about $828 (excluding the taxes I paid) on a phone that I will never possess. My only option is to pay for another phone based on the conversations I've had so far, and I can't afford that. I am a solid customer, and a review of my account will prove that. 

I am working with a local detective at the police department to pull a nearby camera, and I am contacting the local FedEx distribution center tomorrow.