I finally signed up with Comcast for a 2-year promotion after using Satellite TV services the last 20 years, I am beginning to regret this decision. I have had to call Comcast every month for fees I never knew exist even though it was a Comcast issue each time.
The installer didn't have the right converter box for my HDTV so he suggested I make an appointment so another installer can come out to replace the bad box. For this, Comcast charged me $29.99 which I was able to reverse. The initial service also came with a 90-day free HBO/Showtime trial which I cancelled after 90 days also came with a $1.99 change of service fee (I was able to reverse this fee). I had two phone lines which I asked Comcast to port one line but they ported both lines by mistake and tried to charge a monthly fee for the second line even though no service ever provided (I was able to correct the charges after multiple phone calls).
I have Comcast for three months now and I had to call them every month so far due to phantom charges. Thus, check your Comcast bill carefully.