I got a voice mail on my cell phone, shown as being from 401-369-0705. This coincided with a missed call from 612-808-8171; I don't understand how the call could show one number and the voice mail another. The message started in mid-sentence (evidently a robot that didn't wait for the tone) and was offering me credit, with the condition that I had to return the call today to qualify.
Multiple fraud markers: (1) Telemarketing call to a cell phone. (2) Robocall to voicemail. (3) Insistence on immediate response to qualify.
I finally figured it out. It is the voicemail number from tracfone. To pick up your voicemail messages just press and hold the number 1 on the keypad and then you can listen to the message and/or delete it.