Who called from 8505835582

I have rec. calls with the same unmistakable voice and tone under different phone numbers saying repeated "hello", "hello", hello".  They think they connected with someone because my answering machine picks up.  There is a lot of background noise, so it is a call center.  They do not leave a message and I do not know anyone with the area code 850. Wish I could find out who they are.

called at 1539.  left no message on answering machine.  no caller id. thief

Left no message.  3/5/2017 12:18 PM

They call monthly.   My wife says that they will not go away.   today they called at  12:15PM.