Thankyou Gurvinder same thing happened to me and i got the same rply from chat support plz do let us know whether resetting device helped or not, if it does help i will do it too.
@winwin here is a screen shot
Defenitely there is some app which is draining battery in your case.
On an average in normal mode i loose 4-5% of battery overnight.
You need to check the battery monitor in your phone to nail down powerr hungry app.