Who called from 7129411010

I got billed for a call on my toll free number from 712-941-1010.  It was for 30 minutes but I never spoke to anyone for 30 minutes from that number, which is in Iowa.

It seems this number is assigned to Aventure Communication Technology.
They phoned me but left no message.

Call was at 1.32pm on 5/16/10 and lasted 5.9 minutes, on my answering machine. No words, Just static.

06/20/10 Sunday - Got calls to my business 800# @ 3:58 am (2 minutes / no message) and to my personal cellphone @ 7:30 am (no message).  Solicitation (?) clearly not intended to catch a live body answering!

I received a call from this number yesterday on my toll free number. There was a recorded voice, saying a bunch of curse words, and something like, "Where are you going? You can't walk that far, it's 36 miles". Crazy people, I wonder if this is a SKYPE account