What did your chat logs say?
It's always stressful when other players aren't playing to our expectations or picking champions that fit our ideal team comp, or ideal strategies. There's a lot of ways to push advantages and still play to win. But, if others are intent on making the game a negative experience, then you can either report them in the post game or attempt to defuse the situation in an appropriate way. I usually try "Let's just focus on the game please." If they're not willing to do just that, then they aren't going to respond positively to any other statements.
If you were punished, you were doing something more than 1 line of "...please report." It only takes 1 report (2nd Bullet point under "Things to avoid": https://support.riotgames.com/hc/en-us/articles/201752884#h2q1) to trigger a review of someone's game.
While calling for reports is negative, they generally are not the sole reason for getting a punishment, but are a part of a more consistent negative comms in a game. It's also useless, as it only takes 1 person reporting to trigger a review.