Missing Voicemail

Yesterday I had a missed call and the person left me a voicemail. I listened to it and hung up. Today when I went to go back and listen again and get his phone number, the voicemail is gone and a record of his missed call is also gone. How could this happen when I literally did nothing but listen to it. I did listen to it through CarPlay if that makes any difference, but I also did listen to a second voicemail left after that and it is still on my phone. I have checked deleted voicemails and there is nothing from yesterday in there.