Getting really tired of toxic premades

Support Teemo that feeds his lane along with the duo'd Draven, then acts like they were providing more than myself (4/1/3 or something like that before we grouped, ended up 7/6/8 because fed Skarner and Alistar are not fun) with "map awareness." Meanwhile, the Skarner they fed proceeds to devastate our team since the Teemo and Draven put up no wards, just shrooms. Even those were scarce.

Duos autolocking at GOLD/PLAT MMR and feeding, before acting like the rest of the team made them lose lane.

Look, I love premades. Some do things for fun, like Yasuo/Alistar bot or Medic/Dunk Squad. Duos often have the best communication since they know each other to some degree, and duo bots make great plays in most cases. However, I'm getting REALLY tired of the cancerous troll duos that use each other to piss others off while thinking "I don't care, I have a friend with me." Toxic duos and premades also make surrendering impossible, and it always feels like two trolls make an experience four times as bad.

I can't personally give many suggestions off the top of my head, but there has to be SOMETHING to help stop duos and premades from thinking they can be assholes just because they're with friends. Maybe a tweak to the report system so toxic duos/premades can be reported together and dealt with more swiftly and harshly? Although, this would require Riot showing who was duo'd with who at the post-game lobby and I'm not sure they'd want to do that.