Cannot Connection to Internet

XFi with comcast so far in my experience. Got it because of overage usage monthly which I was to told about when I signed up. And now the xFi is down for unknown reasons Comcast wants to charge my $70 bucks to have one of their technical come to my house to find out why their equipment I'm renting and paying for it . Who's running this company? I'm so disappointed with Comcast lately it's not funny, and really am thinking of cutting the cord seriously with them.