I am a teacher. I often work in prisons and cannot take my phone on site. I have tried countless times to get a reader from Abbott but have found it impossible. They say they will 'escalate' my query but they phone me back during the day when I cannot access my phone. I never have a missed call from them but they always leave a voicemail - weird? They will not speak to me via e mail. I am so frustrated. Any advice?