If you have borrowed you should pay.
In India you can lodge complaint for harassment against Indian agents that are harassing you.
Since you are answering their calls and asking information to authenticate they should not contact anyone other than you.
If calls are recieved at Pune then Pune police should have agreed to lodge your compalint.
Try by meeting the higher police officers, lodge compalint by email and letter under proper acknowledgment for your own record.
Contact local counsel.