Just a few questions to start with:
Have you had Comcast's free Norton installed on a previous device (PC ,Laptop etc)?
Have you had a previous Comcast Account in another location?
Are you sure you logged into your Primary Comcast Account prior to starting the download of Norton.
Have you removed any trial AV that could have come installed on your new laptop?
Please see the folllowing - it may be of some help:
Norton Chat Support is not available at present time, but you can go here and select the "View Local Phone Numbers" and go from there.
<EDIT> Here is an addtional link you can look at!
... View more