To speak directly with a representative at Comcast, call their toll-free number: +1-(888)-416-6552. You can also reach them at +1-(888)-416-6552 or @+1-(888)-416-6552.
Never pay down a deposit in a bank account until you have met the seller, seen signed a purchase agreement.
No serious private advertisers ask for a down payment before you meet.
Receiving an email with an in-scanned ID does not mean that you have identified the sender. You do this on the spot, when you sign a purchase agreement.