Poor Service from ADT

ADT installed an Alarm system in my home in March 2023. From the date of installation the system failed to function. Reported to their call centre on numerous occasions to no avail. They keep sending Technicians the last Tech isolated the problem to be the Control Panel 3 weeks ago. To date no response from ADT. I am now considering taking my case to the Ombudsman. I am also asking for a full refund. This company does not care for its Customers very poor after sales service.