Why is this right

So I was loading a game as singed. I ended up having to join 6min late because my game wouldnt load. I got to lane our Rumble jg covered for me and everything was fine. Then about 20min in they start harassing me because im 3/6. I literally said nothing to them. They were treating me like I was their mortal enemy and I had done nothing but play to my best ability. I had an ashe, a rumble, and a naut harass me. (the fizz just said "lol singed is so bad). Basically what I think is unfair is that if I were to report them, the only thing that'd happen is maybe like a 5game chat ban. I almost cried looking at the things they said and im sure other people feel the same way too. I'd just like a better penalty system is all.