Disgusted at the service offered by ADT

My mom was disconnected from the service unkowingly for 4 months and was still charged the premium each month. Her alarm went off and no one from ADT called or responded and that is the point she realised that she could've been in danger and no one would have known, even after the premium was debted from her account. This is extremely concerning as she lives alone and I put my faith in this security company for my mom's protection. The employees and management at ADT were disinterested, and blamed the disconnection on a technical fault. They refused to refund my mom for the 4 months that she was unknowingly disconnected which is disgusting as it was fault off their own. No responsibility was taken and ADT blamed technicians for the mishap. I am utterly disappointed and extremely concerned that this is the service and aftersales service and treatment they provide to paying patrons