Who called from 7089209999

these people have called 41 times...we don't answer the phone when it's not a number that we recognize.

I saw this on my caller ID. I was not home when the first call came in (3/25, evening). The same caller ID appeared this afternoon with the number 708-202-9999. When I answered the phone, no one responded. I heard "air" but not a dial tone, so I hung up.