Alarm installation not completed after 5 weeks

I contacted Fidelity Security to do an assessment and give me a quote for installation of a security system.The quote was given and accepted and installation would commence after payment of a deposit. I paid half of the amount as deposit and waited for installation to commence. After a week I enquired why nothing was happening, and on Saturday at 15:00 a technician assisted by his son and a friend (neither in the employ of the company) arrived to do the installation. This was obviously not completed and they undertook to return. After another enquiry by me they returned to complete the installation, but did not install the hardware I was quoted for, and only inside, because none of the outside hardware was available. I enquired again and after another week the outside beams were installed. Completely wrong and not according to minimum specs. I complained again, but to absolutely no avail. After a month since accepting the quote I asked that it either be corrected or removed. All I got were excuses and promises. I then phoned the regional manager, who undertook that everything will be solved by yesterday and he will give me personal feedback. Neither happened. 5 weeks and counting