Erroneous charge, possible fraud

I had set up to pay my Comcast/Xfinity bills by direct withdrawal from my checking account.   This has been happening for more than 10 years, usually on the 29th of each month.   My checking account was debited by "COMCAST" on Nov 29, 2021, as usual for an expected amount of about $200.   The next day, Nov 30, 2021, my account was debited by "COMCAST CABLE" for $979.31.   As soon as I noticed this, I notified my bank and disputed the charge.   The charge never appeared on my online Comcast account, i.e. there was no billing for $979.31.    Either (1) someone had obtained my checking account number and routing number and intentionally and maliciously took the funds from my account or (2) Comcast made an error and billed my account.   2 weeks later my bank refunded the money to my account, and I have since changed how I pay so that my credit card, not my checking account, is billed by Comcast.   That makes it much easier to dispute charges.   I have tried to notify customer service at Xfinity of my situation, but there is no means for reporting the incident.   I cannot contact Xfinity security and the Xfinity billing department is just too busy to refer me to an appropriate person.   Plus, there is simply the incredible thrashing that one must go through to speak to a live person.   That's why I've written this announcement/post/message.