This is one of my biggest regrets ever. I took on Devcon - from the installation there were issues, and the technicians had to make repeated visits to the house.
Then the alarm kept going off (whilst i was not in town) which resulted in multiple police fines for false call outs. Customer service was never available, the online access didn't work and the option to view in-home photos took 7-9 days to upload images.
Then I discovered an erroneous contract with various contract terms. Registered letters to them were ignored - so I've started a small claims court process.