installed alarm 2 month ago and does not w

Installed alarm 2 months ago and the alarm does not work. First it was the batery that was damege by loadsheding.after they replaced it stil not working. They replaced the radio also no for the 3d time. After replacing the radio it work the next morning it does not work. They take weeks to come and sort out problem and now i need to pay for new things they whant to install and i pay monthly instalments.