looking for something to replace my wife's troublesome zenfone 5.

brand - prefer mainstream brand
budget - below rm700 if possible. add up rm50 max.
specs - better than zenfone 5 will be good if available
additional need - very good battery life.

wife do side online business therefore she will glued to her phone 24/7 with whatsapp, wechat and all those things.

thanks.