The balancers are no longer functioning properly. This could be for a number of reasons, here are a few:
1. The cord attaching the balancer to the window broke. (like you said)
2. The button attaching the cord to the window popped out of the window, pretty likely.
3. The balancer failed and the mechanism inside it broke.
The buttons on the windows are probably applied with the sashes out of the frame, so it isn't something I can fully answer for you, you'll need to check with Caradco.
Contact Caradco, let them know that you have been injured by the failure of their product. Tell them you would be willing to forego any legal action if they help you correct the problem by A, instructing you how to correct, or B, them coming out and fixing them. To hell with the warranty BS, it's probably long gone. When they hear injury lawsuit, they'll send a rep, or be glad to help. If they don't, hire an attorney, you might get a whole houseful of windows.
Please keep in mind Brenda, that a lot of people at Caradco worked hard to put your windows together, and be reasonable in dealing with them, it'll get you a lot further.