Share your experience!
It could be related to some apps you have been using. Check out this topic:
http://talk.sonymobile.com/t5/FAQ/Battery-time-and-enhancement-features/m-p/347874#U347874
Have you given a thought that maybe the battery is defective?
You might need to contact your local sony team and arrange something.
So you didn't buy it directly from Sony? This mmeans the retailer needs to handle any problem you have.