Phone not battery.

[JessiePalmPixi]

My husband and I have the Palm Pixi Plus. My parents are generous enough to allow us to use them for a cheaper price. Well, since we've got these phones... all they have been is trouble. Major problems?

1.) Switches from Volume to Vibrate, randomly. (We've gotten used to this)
2.) Randomly shutting off. (Annoying, but we are patient.)
The issue that is now bugging us, and we'd like all the help we can get from you guys.
3.) Husbands phone shut off and won't turn back on.

I've tried charging it. The paper trick. Holding the power button. Hold Power Button and flick the sound switch 3 times. Nothing. So, I thought "Maybe it's the battery." Nope, not that because I just put his battery into my phone and it started right up. While I put my battery into his phone and NOTHING!

This is geting annoying and we need this fixed, now.