Incoming calls go into voice mail on the first ring

Incoming calls go into voice mail on the first ring. I called comcast customer service and after a long wait was able to talk to a "live" person. She put me on hold and after a long time ,came back on line and told me to hang up the call and she would call me back, which she did and everything looked like it was working . But the next day the same thing occurred. IF I don't get this resolved soon, I am going to cancel all my services with xfinity. I would like to EMail Xfinity customer service, can someone give me their EMail address.