Who called from 3133550996

Just got a robo-phone poll from the same number a minute ago.  Asked about the 18th disrtict State Senate race, when I tried, three times, to respond for Pam Byrnes the call disconnected.

calls all the time

I just did. I didn't pick up, but they called twice in ten minutes' time.

I got a call from this number tonight around 7:30

This number showed up as a missed call on my cell phone.  When I called the number back, I got this message:  "If you'd like to be deleted from my calling list, leave your number after the beep."  Needless to say I didn't leave a message, but what's going on?