called 2 days in a row.  No message left!!!

I have received 3 missed calls from this number (one today and two yesterday). They have not left a message.  

I have received 2 missed calls from this number and no message was left. So I called that number back and an answering machine stated if I wanted to be removed from telemarketing list.

got  a missed call from this number when i called it back it was busy

Have received many calls from this number and they never leave a message.  I never answer any call from a number I don't know.