We went to the Digitone Call Blocker about 6 months ago, and wish we did it sooner.
It blocks up to 80 numbers and will block automatically any spoofed or out of area numbers that Comcast will not block. It cost $100 and you can check it out on Amazon.
There are others that you can use your computer if you leave it on all the time so you might want to check that out also.
Good luck.
