I come across this issue much as well and this isn't even in ranked games.
Usually the best thing to do is watch this video and be thankful that it wasn't this bad: https://www.youtube.com/watch?v=QyQj...ure=plpp_video
But seriously though, I think the best thing to do, besides forming a team is playing random or ranked until you find a fair number of people that you actually kind of like, then just playing with them. Or form a team, might work.
If you're actually playing a game, don't get trolled, and remember to never feed said troll. If they're trolling just tell them to chill out and play the game instead of freaking out, reminding them that it is just a game. If they don't improve, report them and go about your day.
Furthermore, if you see someone being attacked verbally by their teammates, try to defend them as best you can, be the white knight of the game. If they really are doing terribly, try to offer some advice on how they can do better, and maybe even report them for "unskilled player" with the hopes that they will be placed with more suitable players in the future.