Charged for service never received

A few years back when I moved I got a promo that included streaming cable TV, I was told I didn't need a cable box in order to watch I could just stream the channels from the Xfinity app and/or the Xfinity stream website off any device. For years I have been missing channels and/or having the service not working, each time I would call and talk with support I would be told to just clear my browser history, restart my computer etc...  Most recently I called again because I could not get specific channels that I was suppose to get and so I was sent a technician who said that our tv isn't compatible with the service and that the only way to get the cable channels is to get a cable box. Why wasn't I told that a cable box was needed in order to receive the channels??? All this time we have been streaming the free channels yet paying for it, while everyone else who has Xfinity internet gets to stream those same channels for free??? Why is it that when I filed a dispute it is closed without resolution within a few days with no explanation as to why I was charged for service I never received?