GOT A FAKE CALL FROM A GIRL

I got a call from a unknown number saying she is my classmate . and asking for my personal info. i got scared and immediately send my recording with that girl to my mom after that my elder brother call her back and to get who she really is but she refused to talk with my brother, she was just want to talk with me . I don't know how she get my number and no one was pranking with me becasue not that social