Being charged for two flex boxes even though one was stolen.

When I first initially ordered my internet with Xfinity I asked for ONLY my service & the modem/ kit. My first package was stolen at my apartment complex. I called customer support to get another one sent out & explained what happened. I also filed a claim with UPS about my stolen package. They said they would overnight my Xfinity modem/ kit to me. I was overnighted a flex box..

I have NO internet and never even requested this, but I decided to keep it since I was told (after calling back) that it was free since it was just the one. They're supposed to be sending me my internet kit AGAIN even though it's now almost 2 weeks without internet since signing on.

Today was my first day looking through my plan/ bills online since their apps refuse to load on my phone or iPad and I'm being charged for ANOTHER FLEX BOX from the one they sent out to me? The one I NEVER ASKED FOR. Everytime I call and ask about this I'm being told I'm not being charged for it....yet I am. 

I also have my intial modem and another flex box on my account from my first shipment **THAT WAS STOLEN** even though I told them it was stolen. Why is this stuff on my account and how can I remove it?? I can't even return the original flex box to remove this monthly charge so I'm paying for two things when I only have one. :/ 

Customer service has been no help on this front whenever I've called.