Q: how do I delete tv episodes permanently from download queue?

I selected a couple of free episodes that I no longer want, and don't want to download. I've deleted them a couple times, but they keep popping back up and trying to download when I open iTunes. How do I kill them permanently?

I have never let them download (because I have a slow connection), do I have to do that before I can get rid of them?

thanks

kmbr