Both yours and Madhurima's plants look very much the same, but Madhurima's plant doesn't look as if it's in full health as the leaves are drooping. The veins on the leaves of your plant are quite prominent where as Ficus leaves tend to be less so. My suggestion that Madhurima's could be Ficus now seems in doubt.
This link below may be helpful if you have time to read through it.
I like the soursop idea. I found a chinese white olive that was similiar but the the habit and stem really looks more like the soursop. Give it an aspirin, more light (its a full sun tropical) and do not water it too much. Think moist but well drained. After it recovers a little while, think about ensuring a mild fertilizer that has the micronutrients also.