Tv freezing

Why is my tv freezing every 20 minutes!! The only one that freezes is the tv in the family room , I’m getting so tired of this. Comcast charges an arm and a leg for services and we have to deal with this. Everytime I call it’s the same thing unplug it wait 10 seconds plug it back In. Well I don’t want to do that!!! I want to watch a movie with no interruptions. Please someone help me !!!!!