Toxic player in champ select who probably wont get anything for what he did

Probably we all encountered a toxic player in champ select who flamed us for no reason, banned our champ and made us dodge (better -3 lp than -17). The thing is that you cant report them since you didn't play a game and ticket system is not the best either. They can do this pretty much always and get nothing for it, and I don't think that's fair at all. I just got on lol, wanted to play a ranked game and met this toxic player : [image deleted] (he flamed me for no reason, we never played together before, banned my favourite and most comfortable champ and then proceeded to flame more with his premade)
I told him that what he did was not okay, he said that he only had a shitty day and that he let his anger get on me. He gets away with nothing while I lose at least 10 minutes (with some luck) and -3 lp. Riot do something please... Not only does this ruin someone's day, but us people who are at least kind of friendly will stop trying to communicate with our team cause someone may flame out of the blue