Issue with trade in

I switched to Xfinity Mobile on September 20th. My bills issue on the 4th. My October 4th shows my line canceled, but the total amount doesn’t reflect my phone payoff too. It does show my remaining device balance in the device plan section of the bill. I won’t get my last bill that shows the device payoff until November 4th which is outside the 30 days. Xfinity took my phone when I got my new one. Can I submit the October 4th bill? Or what do I do? 

Lastly, the website for trade in doesn’t work. I clicked the link in my email and I continue past xfinitys page and I get an error saying user does not have account.