caller leaves no message and does not answer when I returned call

I called them back and the lady who answered said, "Math Made Easy." I have never heard of any such company and don't know why they called my mother's phone. Maybe they got the number online somewhere.

Caller was male and left message that said in a whispering voice, "Hi miss." Miss you "B"  explicit.  Then said something I couldn't  understand.  I also heard another phone ringing in background.  This is very upsetting that this person would leave a message like that on your voice mail.  I don’t  know anyone in Brooklyn NY!