Someone is kill-stealing on purpose. Is that considered punishable offense?

So earlier today, I was playing against bots and there was a silver playing . During champion select, she called top, along with . However, she didn't stay in that lane. She was moving constantly from lane to lane, and she took all our kills, even if we all had the potentials to do it ourselves. Everyone was upset, so we told her to cut it off, and she refused. Pretty annoying. Just saying, that should be punishable offense.