Do not call that number..
That number itself is the virus, and they would charge you several hundred dollars and who knows what they would put on your machine.
Norton cant pick it up or else norton wouldnt have let it through, this is true for any antivirus, they all leak eventually.
Instead. try this free program, usually, it can find anything that slipped by your antivirus.
Download, install and run hitman pro.. It scans fast.. Let me know if it finds any red or grey items and then click next and then click activate free license, then enter your email twice. And then click next and have it remove what it found.
Then, restart the computer and send a reply and let me know how the machine is running after a restart.. We may have more steps to do afterwords, but wont know till we get there.