I purchased this same phone, and have the same problems. It seems as if I now live my life permanently seeking an electrical outlet so I can charge.
I have had multiple Android phones, and tablets - so I am very aware of how applications and settings effect battery life. This phone is particular is one of the worst I have experienced. I really like the phone - but if I could do it again I would have chosen something else due to this one issue. I can't return it, because I have now had it over 14 days.
I think more people should complain about this issue, because it's not the users' fault in this case. You can have this phone's abilities completely limited and not using a thing, and it will still drain battery so quick you'll form the habit of keeping your charger in your pocket 24/7.