On 8.6.2014 I received a call from this number, too. No caller ID. I did not answer and no message was left. Interestingly, I had recently been on the phone with Blue Cross/Blue Shield, as "scamfighter" stated the caller represented themselves, when spoken with.
I talked to blue cross illinois yesterday. This # called@ 5:30pm mt time/ 6:30pm illinois time. I missed the call, but there was no message left. Could it be just checking back on their customer service?
Agreed, same here called to check for certain procedure if it's covered and they asked for my number should they need to call back and then today I received the call from(630) 517-0521 two times two hours apart, I didn't answer it seeming I didn't know the number nor did they leave a message.... Think I'm going to let FTC know, something isn't right.