Cancelled Service and Bill

[BLUESUPREME84]

I closed out my service with Verizon for my MIFI service.  I was told that there would be a cancellation fee.  I am fine with that.  However why am I being charged for a bill payment when it was cancelled and closed before my due date.  I no longer need the service so why would I want to pay for an upcoming month on an account that is closed.  And also telling me I was passed due when I closed the account at an Verizon retailer 5 days before the due date.