Can someone explain how cable companies can get away with this?

I’ve noticed that cable companies can charge you for service in advance and if you are a day late you can be charged a late fee for services not even rendered yet. How is this possible. Why can’t they make the due date the last date of the service. Then I would understand if you get a late fee. Other than the fact that they do this because they can, why would it be legal in the first place. Actually they are a sub contractor for the cable company. So they don’t even really do anything but charge for possible work that they don’t do most of the year. They only come out and adjust the satelite if its thrown off. The actual satelite company takes care of the day to day and doesn’t even involve them unless its something they need taken care of at the residence.