Tactless - POPI - Calling people to trace someone

Earlier received a call from Sandra stating she was from NDA and was asking me if I had a contact number for XYZ (name). Told her no I am no longer in touch with him and asked who NDA was and why is she calling me and why she is looking for him... she told me because of POPI she can't share. Well because of POPI I can't share the number and wondering where she got my number from that would link me to him and why call me to give a number or leave a message if I could. Tactless. I of course traced the number Sandra called me from and it's linked to this attorneys office. Tsk tsk.