How long do payments from collections take to process?

I recently moved and it took me a long time to get Xfinity their equipment back to them because of where I moved to. So there was a bill that I owed Xfinity and they sent it to collections. I made the payment to them via their Valor Comcast debt collection company but the charge is still there.  I am just wondering how long until Xfinity realizes they have the money and I owe them anything.