Copy of Final Xfinity Mobile Bill

I unexpectedly had to move out of state and cancel my Xfinity internet and mobile service. I thought I downloaded a copy of my final bill/statment, but did not and now need a copy urgently related to an active homeowner's insurance claim. I spoke to two online agents, one who told me there was a technical glitch and to try again later, and the second who told me my only option was to physically go to a Xfinity store. I drove 160+ miles (a 3.5-hour trip each way) to get a copy of this bill. 

When arriving at the store, I had to wait 20 minutes and was then told they had no way to access the account or bill because service had been ended. They then had me do a video call in the store with another Xfinity agent, who kept repeatedly saying the easiest optionwas having the store print it. The store could not figure it out. 

I have now wasted more than 15 hours of my time and an entire tank of gas (in this economy) trying to get a copy of the bill. Can someone PLEASE tell me how to get a copy of this statement; surely Xfinity retains customer records for a period of time, so it must be accessible by someone.