Fidelity ADT - Unacceptable

When Fidelity came to give a quote on an alarm system, I was informed that I should not go for the promo (free) system as the system that I had installed were good. I paid for additional sensors and beams. I have struggled to arm the system for ages and my requests for assistance was ignored. When I complained again, the dealer phoned me and said that my Texecom system cannot be supported by them and I will have to pay a private company to fix the issue. I then informed them that I will be terminating my contract. The private specialist came to review my system and he said that the setup was completely wrong and the zones were also programmed incorrectly. It took about a whole day to sort the mess out. I gave Fidelity notice almost 6 weeks ago. They phoned me today to assist with fixing my system. I then said I gave notice. Then a customer service agent phoned me and requested another chance to resolve the issue. When I said it was too late, she then said I will be liable for early termination of my contract. I had a ******* at my place and then they want to penalize me further for a service that they cannot deliver to me. Then further insult was that I received a warning letter for excessive call-outs for a system that they cannot fix. How does that work? Extremely poor service and sharks. It is all about money for ADT and not about protection and safety.