Sorry to hear of the issues you're having with your device. That's not good. I'd be more than happy to try to figure this out for you.
I did see last year this was a known issue with this model, the device would freeze and would only come back to life with removing the battery. A software released on 03/28/2012 should have fixed that issue for the Marquee. Let's check to see which software your device is running on. Tap the Menu key, go to Settings/About Phone, in this screen you will see your software. The newest software update is LS855ZVC, is that what your phone is showing? If not, check for a software update, in the same screen at the top Tap System Updates, then Tap Update LG Software.
Please let me know how this goes, I will look into other options for you.
I have an LG Marquee. All of a sudden today the screen locks up and I can't use the touchscreen to unlock the phone or use it. I have tried to remove the battery and start the phone back up, but when I do the lights on the home button go on and off and the screen locks up again. I have not been able to make it to the local Sprint Store yet to get this checked out so I thought I would put this out there for any suggestions. Thanks in advance.