I was charged for another month of mobile service even though I moved my service 3 days before my current cycle (already paid for) was over

I saw the bill was posted to my credit card but there should not have been a bill as my final month had no overages to cover

disputed the charge with my card company and now I received a notice from Xfinity mobile that my account was disconnected (this when it was disconnected and moved by me a month prior