Comcast Xfinity Denied Refund Maryland

I had called into Comcast to make a payment agreement.  I never set up a pre-arranged payment because I want to control when the money is actually paid.  When it came time to pay the bill as agreed, I paid it two days early.  However, on the date of the agreement, Comcast took out the payment again.  I called them and asked for them to refund the payment because I had other bills that had to paid with that money.  Their accounting department denied my request because I still had a past due and they put the rest towards the current bill.  I was informed me that I had set up a pre-dated payment. through their computer which was not true because I had set up the agreement date with a CS representative.  Comcast just used a card I had on file to take that payment.  I have since told Comcst to remove all payment cards and accounts on my profile so that this would not happen again.

Still they have denied my refund and I am forced to go through my bank and their dispute process may take up to 90 days.  This is ridiculous.