Received a few call asking for contact details of some but would not say who they represent or what it was about. Also called from blocked number so have adopted no number, don't answer

I called back number (07) 3422 6562 was put on hold music but no one answered the call.

Hi, I received a call from an Indian lady searching for someone I haven't seen in about 15 years. I don't have the information and was wondering whether I should help her out. She wouldn't give me much information on why she was searching for this person other than a "Business matter".