Adt - bad service

I gave ADT one months notice in writing. I have emailed and called them to request that they remove the Alarm system and radio as soon as possible, as the new owners do not want an alarm system. ADT have not bothered to contact me to arrange removal of the alarm. The new owners have since moved in. I keep on emailing and calling ADT, but they cannot confirm when they will remove the alarm. It's been almost 5 weeks.