Intermittent service from comcast

I have had problems with my internet and especially phone service with Comcast for at least the past two months. I have had two Comcast techs to my home in the past month or so. Most recently, a supervisor came to my home and said that Comcast has a network problem in SF. My biggest complaint is that my phone service is intermittent. I live in the Balboa Terrace neighborhood. No dial tone or no one can hear me.