when someone tries to force you out of your lane

How do you react when you finally got first pick after 10 freaking games of being 3rd, 4th, 5th, amd you finally pick what you want in the lane you want, but some other idiot in the 3rd,4th,5th pick considers your pick a troll pick and they pick a champion for your lane and call your role?? And you scream in chat to not lock it but they do....

It's really one of the worst things that can happen to you during champ select. And what if you can't dodge cause you are in promos or you are low in lp.

How can you deal with a person who does that?