I never received a final paper bill from Verizon either. I was able to login using either the account owner's phone number or username (can't remember which one worked, but one of them didn't). I was given access to my last few bills and an option to pay the final one.

If that doesn't work, I found this page which might give you access to your bill:

http://www.verizonwireless.com/paymybill