I didn't flame) just 2 times
There's not a requirement on how much you have to contribute to a negative environment for the other players for a report to count against you, you just have to do it once. If you are capable of "only" flaming twice I think you're perfectly capable of "only" not doing it at all, shouldn't be a big leap.
Consider the consequences of your words before you type in chat. Flaming your team never produces positive results, and usually just makes your team play worse. Try to work with your team to win; if they aren't playing up to your standards you can try to advise them, but they aren't obligated to agree with you, and if they are intentionally playing poorly it's not worth arguing with them. Just focus on the game and try to work with what you're given.
https://support.riotgames.com/attachments/token/hhzvrq225sskft5/?name=Details+Path+to+Victory+lux.png
Our statistics show that chances to win decrease by roughly 10% for each toxic player on any given team. The opposite is also true, as the chance to win increases significantly with each positive person on the team. Being that beacon of positivity is often the difference between a victory and defeat.
As human beings, we are often quick to judge but slow to praise, especially when it comes to strangers. Try turning that around – highlight and compliment achievement of others during a game. It does not matter if the achievement is game changing, or even significant. It encourages people to play and perform better than any critique ever could. Positive reinforcement wins games more than any champion, skillshot or ultimate. Also, you are nearly twice as likely to not get reported while engaging in positive reinforcement!
https://support.riotgames.com/hc/en-us/articles/201751874-Behavior-Worthy-of-a-Champion