Toxic Pre-made Threaten to Report Me

I was playing solo queue with a three man group, jungle, mid, and ADC were a party. Mid lane was very toxic to our top lane Kog'Maw, so I told him if he did not stop being rude to Kog that I would report him. That is when I found out they were a three man group, who all said they would report me for toxicity and Riot would take it more seriously since there are three of them and one of me. After this, the three of them were toxic to me and Kog for the rest of the game. I reported two of them, the other wasn't so bad. I also wrote a description to Riot of the events that happened and requested they review the in game chat to see who was actually being toxic in this game. I am a little worried that Riot may not listen to me since it was a three man group. How seriously do they take this type of reports? Do they usually pull up the game and verify whether or not a player is being toxic? I just don't want any negative points against me. I have a level 5 honor badge, and always try to be a good teamplayer, even when it's very hard, lol.