Payment Reversal on Autopay has led to upcoming charges which I cannot view; is my bill even paid?

I recently signed up for an internet plan with xfinity. Things were going fine, and I enrolled in autopay to make billing an easier process. I was told that my bill was paid by Xfinity only to be informed a week later that the payment was reversed. I was completely unaware of this, though it looks like I have now acquired a number of fees or "one-time charges" thanks to this. I don't know what to do and my bank hasn't been much help yet.