I was having the same issue. I tried everything at the modem, the phone lines and online. Nothing worked. The phone would ring, I would answer and nobody was there. The calls were going straight to voicemail. I called for technical support and the offshore rep was not able to fix the problem and said a technician would have to come to troubleshoot the issue. I asked if this was going to cost me a service fee. The rep assured me there would be no cost to me since the problem could not be taken care of on their end. My November bill has a $70 service fee. My phone is now working, the tech used his phone to call the center to explain what needed to occur to fix the issue. I hate comcast.