First question what is the amount  we are talking about here that went to wrong account a friend of mine did something similar last week but the other person that time was nice and returned 25K INR ..? In your case if the amount was less than 6 digits then the chances are on lower side that you'll recover it as you know Police won't take much interest unless they are getting their cut out of it.

 But I don't understand why they  said that chances are almost negligible I mean you have all the required bank details and i think those are enough to track him down. maybe the reason i mentioned earlier is the case here.