Harassment & threatening calls frm debt coll. of Kotak Bank

Hi Sir, I don't know if this is the correct forum or not. In 2013 I received a call from a lady on Friday stating that she is calling from court tees hazari and there is a case which Bank has filed stating that I am a defaulter of Barclays Bank credit card and have to pay money if I don't pay then Court will get a non bailable warrant under my name. I got scared and told her that I am not aware of this money etc. She became aggressive and to create pressure she shown that she has got every details about me, she told me an old address. I got scared and hung up the phone. She called again and told her that it might have happened in the past that Bank people have called in and it might have been an identity theft as I have never taken money and tried to explain however she didn't listen i hung up the call and didn't pay attention. In 2015 I pulled my cibil to check scores I saw Barclays credit card of some 35000Rs approx. And I immediately put in dispute explaining it's an identity theft and raised a dispute. They asked me to wait for 30 days for investigation. And on 16th July I received a reply from cibil that information has been removed dispute no. D000129054, service request no. 40537055. Now in 2017 my reputation is being ruined and played by a third party debt collector caller/agency phone number 01145082540. I don't have any other info me and my female colleagues have received threatening and harassment calls from this number. Caller calls and states that he is calling from Barclays Bank and want the money. I have explained them the entire situation and also told them that this info has been removed from my cibil however man on phone abused and threatened me and asked me to pay money. I said i will complain to police then the caller said police can't do anything of him. This caller is ruining my reputation by calling my professional and personal contact or knowns and telling everybody that I am a defaulter and need to pay and if they deny about the info caller abuses and use rough language to prove his point. I am scared because of all these calls my job will come on stake also these people do not see time they call customers 10 times in a day. I want these people to stop calling my contacts and known. As proof I have email from cibil that this case is over and this information no longer shows on my cibil. Also I have screen shot of the number of calls where while talking to me this caller has called my colleague 6 times. Also I used Delhi Police App and emailed delpol@vsnl.com. As if now no response. I don't know what to do and how to go about it. Kindly help.