I don't know. I think it may be a credit card company. They leave a message but it's just one of those recorded messages. My phone doesn't ring and no number shows up on my call list.
There is one phone number, I don't know what it is, but someone calls me and my phone never rings and the number doesn't show up on my "recent calls" list. Yet they do call and leave a voicemail. How could this happen?