ADT Security Systems Brinks/ Broadview Security system ripoff multiple, Internet

If you have a working home security system in your house and an ADT representative or TV commercial tries to convince you to change to ADT, RUN in the opposite direction as fast as you can.  When we built our house, we had a security system installed as the house was built, so it was prewired into the walls, etc. Then installed and activated after the house was finished.
A few years ago, I was at a Home Show and a Brinks representative (Brinks is now ADT) convinced me to use their service to have my system monitored. Well, their technician came to the house, ripped out the Main control panel and put in their panel, and rewired the whole house with all new zones. Soon we discovered that about half of the windows and some of the doors didn't work with the alarm, meaning when you opened them, nothing happened with the beeping that should have been heard everytime you opened a window or door. That meant they were not on the system. Probably intentional, so someone could enter even if the system was turned on. Anyway, when my contract ran out I told them to cancel my monitoring service. After a few months, I got a huge bill, for "monitoring" for a lot of months, so I sent them an email that I had cancelled the monitoring, so they called and left a message on my phone on how to deactivate the monitoring service. Well, it disables the entire system, so now I have no working system and all they have to say is "the equipment belongs to ADT and you can't have an alarm system unless we monitor it". That is a RIPOFF.  I had a working alarm system before I went with their monitoring, and now I don't have my equipment I paid a lot of money for and I have their useless equipment in my house and they won't do anything about it. So BE WARNED They will rip you off big time, unless you pay them each month with a BIG contract.