Reschedule payment arrangement

I just sat and typed out my entire dilemma, and I'm not sure it posted. I've been trying to reschedule my payment for tomorrow, and the app keeps giving me different errors with every change I try to make. It wouldn't allow me to cancel it because it said Comcast was experiencing issues and I needed to refresh. After refreshing, I tried just changing the date on my current payment arrangement and when I try to submit that change, I get another error saying "no payments scheduled" or something to that effect. Regardless, you're making it impossible to change, customer service is closed, and my account is going to end up over drafted because I don't know what else to do

 Please help me!