Is this allowed?

As with the release of every ultimate skin, lux has become quite popular recently. In my most recent lobby i ran across two lux mains, duo queued bot together (they both had lux in their usernames and clantags). I hovered lux as my mid champion. The adc then said that if their support couldn't have lux, they would ban her from me. And they did. As i was higher in the pick order, i really felt that i was the one deserving of my choice in pick. I then said that i could play Ahri instead , and the support proceeded to ban her as well. I'm completely disappointed in the lack of punishment for this behavior. If they wanted to ban her because she might be picked from me, fine, but i was first pick in the draft. They did it out of spite - and i can't mute them in the lobby or anything. I ended up dodging, but someone being able to waste my time like that is disgusting and makes me want to drop the game all together. Thoughts? I'd really love a new report system where you can submit screenshots and report on the league website instead of exclusively in game, but if Riot had the resources to care about this issue i feel like they would've implemented something like that by now.