Who called from 2520000000

This phone number has been calling at 9pm for the past two nights and hanging up.  Don't know who it is or if it's even a real number?  Weird

I answered a call from this number and the person on the line told me they were conducting a survey about the upcoming Nov elections.  I told them I did not want to participate in this survey and I asked to be removed from the calling list; however, I received a call from the same number the very next day!  Too  bad the Do Not Call Registry doesn't apply to political organizations...