No message left, but this number has called my phone twice a day for the last two days. Nothing on the other end when I bothered to pick up, just a disconnect after a few seconds. They're possibly identifying active numbers to spoof. I recently made the mistake of reactivating an account at FastWebs, after which I started receiving 5-15 spam calls a day. Yikes.
Scammers claiming to be with US Government grants or IRS its a Community/Tech college number and recording on call back apologizing for the use of their number.