Doesn't leave a message.

Blocked call #511.

312 283 3786 5/16/16 3.15pm did not leave message empty vm message
I called back, it said this Survey is now full.

I am also in the Chicago area and notice most of the junk calls are now coming from Chicagoland area codes.  My guess is that they aren't really calling from this area, but rather just spoofing area numbers to make the person called more likely to think it's a valid call and pick up.  My guess is that this is happening all over the country, since numbers are so easy to spoof.

Received a call from this number but did not answer. No voicemail left. Did not return call.