DND does not direct calls to voicemail, it just keeps your phone silent and doesn't ring/vibrate while the incoming call screen is showing. I've still accident

DND does not direct calls to voicemail, it just keeps your phone silent and doesn't ring/vibrate while the incoming call screen is showing. I've still accidentally answered calls while in DND mode. Sometimes I just want to turn phone calls off entirely and use my phone like it's an iPod touch with a data SIM card.