this lady that called me treat me that my number will be disconnected

Receiving threatening phone calls from this number.  They call and ask for your name and birthdate and don't even tell you what the call is about.  Then when you ask what the call is in regards too they get all threatening and demanding.  They also call people quite early at 815am.  I  do not have anything outstanding so to receive phone calls like this is quite frustrating and make you not trust anything.