trolls banning champs on purpose?

Ok i was having fun playing was in a good mood. Then i get a troll lobby. I get my secondary in a ranked not my main. Im like oh well. No biggie i will use mf and ill be fine right. we get to the last ban and this guy who is supposed to be my support bans my champ. Im like you excuse me? Wtf why? He says nothing everyone else is laughing. And im just confused like a "sorry", or a "oops" i wouldn't care but nothing. Won't respond to me in game. At this point i let the troll get me. Oh and did i mention he picked patheon as a sup? He steals my ks only goes in when im dead. And i realize ok he is a troll. Then he just leaves me so im bot all by myself. The rest of the team is losing too so that doesn't help. Now what i want to ask is can you do something about people banning champs that teammates want? Like disable if they have intent on it or make it a reportable offense? I can't think of any downsides to doing this. When i see it happen on accident i see alot of dodges usually. I have yet to dodge and i don't ever want to. I have been lobbied with someone that had a 20 min que because of it and that is not something i want lol.

  Now maybe there is some downside to this i didn't think of but a report option at least would be nice. So repeat team champ banners can be spotted. Just some ideas, i know it causes a lot of grief to a lot of people.

p.s. i was also afk for a sec of this game to check the boards on this subject had trouble finding anything fast enough. Just wanted to know if i need to record the game or what not.