Payment made, service disconnected

I made a payment on a past due amount before my service could be disconnected. It processed and I went about my day. Following day I have no service, a larger past due amount that didn’t take into account what I had done the day prior so I contacted customer service. They could see the payment posted but they said banks had had trouble this weekend so because of that, my family no longer had internet and I have to pay a bigger balance. I paid what I owed but Xfinity isn’t helping. This left a very bad taste in my mouth