Sorry you're having problems with yours. I hope you can get it resolved. At the same time, I have to disagree with your assessment about the quality of the device -- at least on the first day. Of course, it might change over time. Fit and finish of this thing is just spot on -- perfect. Everything fits just the say it should. Everything works the way it should. I've found the taste in some juices tonight that I thought were not good, until I cranked up the power a little on the Hana v3. I have a red one, the battery doesn't move, the LED doesn't shut off unexpectedly, and any of the other problems you describe. I own 2 Reos, 2 Provari, and now the Hana Modz. After one day of evaluation, I think the Hana is going to be my goto mod for the foreseeable future. It's that good -- or at least, mine is! YMMV.
Back to your post -- what battery are you using, and did you try another when you experienced the problem?