Try calling comcast back and telling them, "Look, RCN is going to give me $DEAL, internet + n channels for $79/mo for 3 years, offer me some kind of deal to match that or I'll switch." There *are* people who are empowered to make those kinds of deals but it's not the front-line phone people you deal with right away when you call. Look at it this way, the worst they can do is say "No".