Whether such actions would fall under criminal law or not is a different thing, why did you not stop your conversations with her when you came to know that she is trying to fool you.
Also how can you use abusive words without being provoked.
Whatever it is, the guy who hreatened you over phone in the guise of police is absolutely ignorable.
Do not respond to such calls.
They will carry nolegal validity or any maintainable legal action.
Nxt time when the guy cals you, you can ask his details/particulars and may inform that if he is not stopiing such threatening activities, you will iitiate legal acton against him through appropriate legal forums.
You will stop receiving such calls after that.