Simple solution to trolls banning your champ
I see multiple discussions about trolls banning your champ because they simply think you will suck at the champ or dont like that champ being on their team. Simple solution to this is don't even lock in the suggested champ you want to play and wait for it to come to your turn to pick the champ you want to play, then you wont have any problem with this. If they dodge then you don't have to be on the team with the troll. It's a win/win.
This is mostly for people that come across trolls quite frequently like bronze/silver players. (Where the majority of the trolls are)