Ask to see a copy of the written tarriff. The Comcast site says the regulated rates may vary according to the franchise authority. To me this means it's different if the franchise authority requires it to be different (perhaps I'm being a bit optimistic). At any rate it should be in some document if it's not what the Comcast site claims it normally to be. There's also an email address on this thread if you believe you're being told a line - hopefully the Comcast Cares desk can research what your specific rate should be, rather than giving you a platitude along the lines of "Well, it can vary by location..."