I made a payment arrangement and said "NO" to an auto payment that I would call the payment in on my own.. I called the payment in on the said day of the arrangement using my checking account. Couple days later I looked at my and saw a double charge. One to the checking account and one to my debit card on file. The 2nd charge caused all kinds of over draft charges to my account.. I called comcast and they said there was nothing they can do about it that I agreed to a payment on that day (I agreed to 1 not 2). That I have to call the bank and dispute the payment. This will take weeks if not months to get my money back. I am seriously thinking about filing a class action lawsuit against them cause I have read Iam not the only one they have done this to.
Whomever you talked with was correct in that you will need to get in touch with your bank and stop payment on one of the payments made*. Comcast will only apply the second payment to your account. Stopping payment through your bank would be much faster than waiting on Comcast to go through the channels in order to issue a refund, and then they will only refund the amount made, not any overdraft charges.
*Be mindful that your bank may charge for a stop payment.