SIL's Chi broke last week...the on/off thing. It shocked her good when it went, too. She contacted the store, who said since she bought in October, it has to go through the manufacturer. She contacted the manufacturer, and they said it would be several weeks while they look into this.
So check reviews, see if anyone else is having similar issues. I paid $30-ish 2 yrs ago for a Revlon straightening iron. Mine's fine still.