Don't ever call a number back unless they leave a legitimate message or you know the number. First thing in the morning when I come to work I open this page and leave it open so I can quickly enter a number as it is ringing to see if it's legitimate
When I used some website for this purpose, it comes up that some Maria Perez from Plantation, FL called.
I have missed call from this number, but never called back. If it's Maria's number, then she is persistent since I have two missed calls.