Idiots in champ select

I can't tell you how many times I've asked people to lock a champ for me then I can get whoever they want. But there are so many times where they wait till you have 3 seconds and the lobby won't let you lock. I get dodge timers because of these people and I'm tired of it. There needs to be something to punish players who do this, or who bait you into a role you don't want, such as they offer to lock a champ for you, then tell you who they want then never trade.