RANK SOLO QUE MATCHMAKING IS A JOKE

I'm gonna make this short.

Setting: Champion Select Jax: "Don't ban Tryndamere. I main him." Person Banning: Bans Tryndamere Jax: "Why did you ban Tryndamere?" Sejauni: "Because I don't want anyone playing him. :)" (WHO DOES THIS?) This whole problem started because I was in a lobby beforehand that got disbanded and the "Sejuani" asked "Jax" to play Jax and he said no I don't want to. He wanted to play Tryndamere and he didn't want to play Jax. So someone left and we get into a lobby and the "Sejuani" was banning and that's where everything goes downhill.

(In-game Now) Sejuani is being negative towards everyone and proceeds to call our Cassiopeia that shes awful and shouldn't play Rank. Tells our Jax that he's garbage and shouldn't even playing League in general. He didn't even want to play Jax and now this dude is chewing him out now? He was negative the entire game and didn't even do anything. Never ganked or anything.

I'm deeply confused on how I can win normal game after normal game, but I queue into Rank and I lose almost every game? I do fine and I have to deal with that? That loses the whole instinctive to even play Rank. If I want to lose every game, I'll go play on my normals where I don't mind losing. I'm trying to climb out of Bronze and I can't because I have teammates who don't want to play together and go Rambo and fight a 1v3 when they're 0-2. This is ridiculous.