Call from credit card recovery agent

Hi, I have couple of questions, my Dad had taken credit card from standard charted bank 1997 and it was settled long back by him when I was 16-17 year old.. Long gone and forgotten until recently I received a call from someone claiming to be calling from standard charted bank. And telling me that there is an outstanding amount.. My parents stay in Mumbai and I have shifted to Hyderabad for job.. After checking with my dad I got to know that even he is receiving these calls, but he is ignoring them. 1. Not really sure how on earth they got my number as my dad has never shared my number and definitely I didn't had my current number with me in 1997 when he took the card I was in school. Is my privacy at stake? Do the recovery agency have access to get my information like this? 2. Should we ignore this or we should take some legal actions for this kind of harassment? And what legal action can we take? 3. Should we be contacting with the bank itself? How can I get this clarified? This is frustrating as my dad is above 60 now and this kind of harassment are not good for his health. Please help me with the appropriate suggestions. Thanks.