Last night I pulled an ambush, and killed a heroe on the heroes turn before he got his turn, I then claimed that he didn't get a turn because he was dead that round or something.

Did I cheat?

If you kill a hero during that hero's turn, he loses his turn:

JitD rules page 16:

"When a hero loses his last wound token, he is killed. The hero immediately moves to the town. If it was the hero’s turn, his turn immediately ends. "

But your question is worded as if the heroes have a single collective turn, which is not the case. Killing hero A only ends his turn if it is currently hero A's turn, not if it's hero B's turn.

And if I remember correctly, the Ambush card says to play it before a hero's turn, which would mean that hero would still get a turn after you were done.

I think your players were correct. Ambush interrupts the turn before a hero gets their action. Once the ambush is concluded the hero's turn resumes. If the dead hero had not yet been activated then they would get to go during the turn. Of course they are starting in town so they are not going to be doing whatever they were originally planning on having him do.

I have yet to see any cards that totally negate a hero getting a turn. They may make if very difficult to do anything (ie web and stun) but the hero still gets a chance to act.

Brian

Piling Burn and/or Bleed tokens on a hero with very low remaining health will often cost him his next turn, since those inflict damage at the start of his turn and will cause his turn to immediately end if they kill him. There's always a chance of not suffering damage, though.

Thanks, that clears things up!