Lens won't retract

what you have suffered from is what is called impact damage. The gears inside of the lens are either broken damaged or out of alignment. You can't fix it yourself, but you can get it fixed. There may also be other issues with impact damage, focusing, and you will probably need a re-calibration

http://www.cameradr.com/

He can fix your camera, its cheaper to fix it than to get a new one.

Nate