Who called from 5154783606

Have called at least 3 times daily for last week.  No avaliable options to be taken off list as it is an automatic message.

This telephone number is actually a US Cellular number. If you call it back, it rolls over to another answering machine for some company. Has called daily for a week at random times on different days.

Land line located in Adel, IA. They have called five (5) times in two (2) days.

I have it on good authority that it's a poll regarding some 2016 election challenge to Senator Chuck Grassley (R. Iowa)

This number calls every 2-3 hours.  It is a political survey call that is automated, and there are no options to be removed from their autodial, and no options to speak with a person.  We are on the do not call list so these calls should be completely illegal!