Finding My Phone Without "Find My iPhone"

Greeting Everyone,

Earlier this year I bought and iPhone 6s. Actually, my uncle bought it from the US and shipped it to Bangladesh. A couple of months later someone stole the phone. The "Find My iPhone" was not activated. Is there any other way apple can help finding the phone.

On my support profile I wanted to add my iPhone but when I giving my serial number it says "According to our records, this serial number is associated to with another Apple ID." Which definitely means, someone is using my iPhone.

I just want to find my phone and want to disable it for the whole life so that no other person can use the phone which I bought with my own money.