They own the majority of the TV and internet subscription services?
This is not monopoly. Monopoly would be if they owned all of them, without any competition.
Currently they only local monopoly in some places (like where I live), where they control 100% of "Superfast" market. However this is not considered unfair competition practice at present time (and even encouraged - e.g. BDUK "Superfast" rollout only finances *single* superfast provider in each given area).