Back to square one

So it turns out that the Comcast Digital Box I already have will not deliver HDTV. "Not a problem," say the salespeople, who are willing and even anxious to initiate the upgrade to a HiDef Box. However, when I check with Comcast online they tell me that the HiDef service is "not yet available" in my area. Hmmm. Were those sales folks wrong, or do they have some priority way of getting me the HiDef service???