Never let your Comcast modem break

Unless you want to suffer through five cancelled service appointments and other annoyances, as described by MartiniPundit:

... We made another appointment for Saturday 1-3.

Nothing. I had called about 1:30 to confirm the appointment, but after 3pm passed, I called again. At this time, I was informed that the appointment had been cancelled at 1:03 nearly a half hour before I called and received confirmation that the appointment was on. ...