Dificult to say from a distance without a visual. Do you have pictures?
What have you done the last 2-3 weeks? Did you move it? Placed it in front of an open window at night? Have you changed the watering schedule (Does it sit on a window-sill with heating underneath?)
Fica = Ficus, I presume? Ficus are a hardy species. Dropping leaves is a natural response to changing circumstances. So it is not so that you have certainly killed the plant. Let us know the answers on questions posted above.
Cheers,
Jelle.