I have read quite a lot on this sub about cancelling, and I appreciate everyone's advice and experience, so let me give back a little.
We had Vivint for just over 7 years.
I cancelled today by phone. I called 3 times before I finally was able to talk to a person. I knew this would be important, as there is no way to do this through a phone menu - they will throw all kinds of incentives at you to keep you. But I knew what I wanted, and just politely stuck to it.
The number I called was 800-216-5232. It is on the Support page of their website. There is no option in the phone menu to cancel, or to speak to a representative. I finally just used the option that I am moving and need to change my service address. When a human answered, I told her, "I am calling today to cancel my account with Vivint." She was polite and transferred me to the Customer Loyalty line. (whatever)
I spoke with a very nice rep, who tried to throw all kinds of incentives and discounts at me. I just politely kept saying, "no thank you, I want to cancel my account." Of course they want to know why, because they are going to try to defend themselves and talk you out of it. In my case, I just told them, "We have chosen a different security system, it has been installed, and we no longer need Vivint. Please cancel my account."
I kept all of my answers short and to the point. Almost robotic. I'm not going to get emotional, or tell them that I didn't like their half-assed service, or that the only time we heard from them was when they were trying to upgrade our equipment ($$$). Even when we had 2 of our 3 cameras offline, they never called to ask if we were aware.
She put me on hold several times. In retrospect, she knew she was getting nowhere with her incentives and was trying to locate another agent to escalate.
I am the kind of person who, in this situation, will kill 'em with kindness. No emotion. No sob story. "No" and "No thank you" are complete sentences. I am not obligated to justify to them why I am cancelling.
I was transferred to the 2nd agent. She was dripping with ass-kissing about how long we've been with Vivint, threw out LOTS of discounts and incentives. At this point, I had been on the phone over 30 minutes and was only half-listening, but she tried to throw in several months for fee, a lower monthly rate (we were at $62/mo), a $1500 discount on new equipment. But I stuck to my plan.
By the end, I was able to cancel over the phone, and received an email confirmation. I was on the phone for a total of 45 minutes.
On the good side: It is cancelled.
On the crappy side - its a 30-day cancellation notice. So I have to pay a prorated portion of my last month, out to 30 days from today. I didn't argue. I'll decide whether or not I want to fight it over about $30.