Called and hung up. Called again and asked by name, upon a positive acknowledgement, hung up. I called back and they hung up. I called again and got put into anonymous voicemail.

I had a similar experience. I received a call from 404-418-6321 and it sounded like a pocket call when I picked up (I could hear background conversations, but no one was responding to me) and then they hung up. Called back, got a generic VM. Called again an hour later, someone picked up and said "This is Jeremy" and when I said that I had been called from that number an hour ago, he hung up.

They called, asked for some weird name twice then hung up. Same background noise as mentioned in the previous message.