You got it, Grammy: It's probably a scammy caller; ignore it in the future, don't call them back. If you can, pick up and hang up immediately, not giving the caller time to reach voice mail or anything. They'll stop eventually.
This forum is full, chock-a-block, with reports of similar calls from people trying to scam us.
Idiot just called. She left a message that said, Hello? I have placed a REALLY short message on my system that says, "Leave a message, thank you." That seems to screw up their system and they "think" somebody actually answered the phone. It's my pleasure to waste some of their time - jerks!
Caller ID showed XXXXXXXXXX CA. I do not answer this type of call, and sure enough, they didn't leave a message either. Either a telephone marketer ignoring the DNC list or a crank call, neither one worth answering.