Why does my brand new Blackberry Curve 9330 battery only hold it's charge for about 2 hours?

It is only one week old and has never been used before. I'm not understanding why it wont hold its battery. By about 3:00pm it will be dying, when I need it to be charged until the end of the day. I only use it for texting and seldom for phone calls. Any answers for this problem? Thanks!!