Rescrited access to billing area

I closed out my Xfinity account and was told they would adjust my bill for when I didn't have service and the difference would be payable later. It's been smoe time now and my account still can't make or view any kind of bill. The messanger response tool can bring up that I have a billing statement of an amount that I'm not sure if it's correct, and it can't show me an actual bill. My account needs some adjustment for me to be able to view my bill so that I can see what the charges are for, and that I can pay the remained and close out my account.