This is Comcast. I called back and followed the prompt to be put on the no call list. However, once connected I got a message saying that the mailbox I was attempting to reach is full, so I was not able to say I want to be on their no call list.
This is a spam auto dialer pretending to be Comcast. So not hit any prompts, just auto-block the number.
If you do, then you will receive spam from lots of other numberstuff. They collect these and sell them to other spam companies as valid, in use, numbers.