I have to agree with Da-man. Helis don't just come apart. If it threw a blade, something was seriously wrong. I would get someone that knows helis to go over the entire machine with you. Check every nut and bolt. Check every linkage for cracks, check every bearing for wear and make sure it is not messed up. You got it used so you don't know what it has been through. Those blades could have been cracked to start with and noone caught it. Get some new blades, get it set up right, and get help to learn it and you will be fine. It is a good heli. Sounds to me like there was a problem before you got it. Could have gotten cracked in shipping and noone caught it, could have been from a previous flight or anything else.

Don't give up on it. Its a good machine.