ICICI Credit Card — Harassment calls from a icici bank /credit card from phone numbers originating from location chennai

Address:

Bangalore, Karnataka, 560076

All the telephone calls are originating from Chennai location and it comes as +[protected] /110 /112/105.A person called Kiran called from Chennai icici bank claiming my brother has not paid icici credit card in 2007 and the credit card address is listed for Rajajinagar, Bangalore which is UNKNOWN address even to me.I said my brother is out of India for the last 10 years and he doesn't own a icici bank card since he doesn't have a PAN or ever stayed in Bangalore since he is deputed to UN location. He is asking who can clear the amount but he is not ready to say how much pending amount is there in the bill.He says i have to go to Bommanahalli icici bank branch (Bangalore) else speak to him on his personal number [protected] for the amount pending.
He is not ready to provide his FULL NAME, EMPLOYEE Number, Office Location In Chennai so I can take this matter forward.Please have this checked else i will need to file a police complaint AGAINST unknown members of ICICi bank as this is an harassment to icici bank customers like me.