US Window Factory does not take action for faulty product installation

We had the US window factory change all the windows in our house on 6-5-09, spent $4,662. There is a lifetime warranty also. They installed the windows and left without checking if all the windows work properly. We tried locking the windows with negative results. The top part is loose and keeps coming down in ALL the windows in the whole house and the windows do not lock. My 3 yr old niece was standing with her hands on the window panel and it came down almost crushing her fingers, she was hurt. The windows are loose and often keep sliding down. We cannot leave the house since the windows do not lock, its unsafe and could be burglarized. US window factory sent someone to look at it and said that there was a defective part in the windows and they will order new parts and would soon come to fix it. That was more than a month ago on 7-10-09 and they have not taken any action. We have been calling them and they keep telling us someone will take a look in the matter. I am never ever doing business with this company and will hold them responsible if our house gets burglarized or someone gets hurt.

Update, as of 10-19-09, windows still need to be fixed and it is getting really cold and rainy. Our whole house stays cold and water comes inside due to rain,yet no action by this pathetic company.