Not sure who it is, I get a call every day, but this number has long been in my phone's ignore list, so I haven't attempted to answer.  Calling back gets a computer voice that I will be transferred to a representative.  Most likely a collection agency.

PS: My android phone uses a free app called CallFilter by Telemarks.co.jp.  I highly recommend it for blocking calls.

They just called me. Once they identified themselves and said it was a personal matter I hung up on them. I really have nothing to say to anyone. ALL companies that I deal with have been told and actually follow the rule of no calls during the day. Those who do not listen I do not speak to.

Call came in at 5:13 PM on March 31, 2015 from Bartow, FL. Was on another call at the time. Did not recognize the number and I never answer these calls.

It's a collection agency for Hospitals.