Xfinity will not provide an itemized bill of what i owe

I need an itemized bill of what I owe for the two phones I had with Xfinity. I cancelled my account on July 20th and I had tried contacting them several times. They always tell me to go to a store but when I go they say they cannot do it. They say they will send everything to my email but they just don't do it. What can I do?