That's a bit too harsh, in my opinion. I know that teamers can be really annoying, but all you can do for now is wait for the new ban system. :)
I Think that it should be bannable. It makes the game more fair.
I think that you first need to Give them a warn a to make clear it's not right and than giving them a ban if they doing it againAt the moment, we are only kicking if we see it in-game as the lowest time we can do for any punishment is a month. A month is too harsh for something like this. When the new system is brought out, things should be more clear.