I'm angry at my friends for playing volleyball wrong.
Why do you feel the need to correct them? What else did they do?
I expressed my opinion, but it got ignored because I knew the game was never going to be played right.
It is wrong to get angry at people who don't fully know the rules. It is not a professional game and only for fun so you should be a bit more lenient.
I do not believe that. They are playing the game wrong. I will correct them.
Maybe they are playing the way that makes it the most fun or them. Let them have fun and keep doing what they are doing.