ADT service SUCKS!

Had an issue with my system, it was not arming nor disarming as it should. Notified my local ADT office, technician came out once, issue persisted and in fact got worse. I got a signal booster for myself hoping that would solve the issue, I reported it again to ADT that I am unable to use the system and is not servicing its purpose, when I stopped paying they quickly called me demanding access to my house to uplift the system due to non payment and say I have to settle the arrears! How can I be expected to pay for something that was not functioning properly! They are useless and couldn't care. I contacted their complains department, it’s been over a month and not even a single reply. USELESS!