Who called from 2016800224

"thank u for calling hey cosmo please hold while we retrieve your information" I just hung up

Received this call to my personal cell phone.  No caller ID, no one spoke, no message.

What the heck! I got a call from this number when I didn't have my phone and they left a voicemail saying this:
Hello this is Carol
please call back when you read this number or something
So please call back in like 2 minutes or else offer go bye bye
(and then i thought i heard people in the background screaming my name)

PLEASE HELP FIND OUT WHO THIS IS!

This number has called me numerous times over the past week  and again just now  18:17 - 12 May 2012.  Arlington, VA with a Texas number cell phone.  Always hangs up as soon as I say hello.

They keep calling my cell. I am also on the DO NOT CALL LIST.       I called back from a blocked number.  It was blank on the other end, but after a while you hear a message,  The company is called Charter Business and HEY COSMO - a free automated telephone service.  I guess they have nothing better to do that bug you.