Had been using ADT for 25 years. Don't know why! Shockingly bad 'service' and rude & inexperienced staff. Issues have included engineers turning up out of the blue & then trying to charge me for visits I hadn't wanted, engineers NOT turning up when they had been booked to & then being told when I've complained that 'THEY'VE decided to come tomorrow instead!' Didn't matter that I'd stayed in all day or if I was available the next day! This happened several times. Had called a few times stating I wanted to install cameras from ADT. Was told each time they would be in contact....bought from a rival after hearing nothing. Had several issues last year highlighted on the App so when finally the engineer did arrive (after 2 'missed' bookings), expected him to 'fix' the issues. He left saying he had....he hadn't! Finally cancelled my contract with them in January which they acknowledged...but they also then proceded to send me invoices for different amounts by post & email threatening to stop providing me a 'service' ! Such a badly run company.