Comcast Double charged / deducted Missouri

 I authorized a payment in the amount of $257.47 on 8/28.  That payment was posted on 8/29.  That same payment posted again on 8/31.  This left me with about $4.00 to buy gas and groceries for the week.  I called Comcast immediately after it happened.  They recognized it as their error and told me it would be refunded within 48 hours.  I called my bank.  There has been no indication of a refund as of 9/4.  Today, 9/5, still no refund!  Definitely the LAST payment I will make to Comcast using my debit card.  You would think that with double billing / charging errors posted by consumers, to the internet, going back as far as 2007, they would have a quick way of dealing with these issues.  I have only been a Comcast subscriber for a couple of month and I am already in the market for an alternative.