Did you check the back tamper was closed, if he fitted the back plate upside down then the back tamper would never work unless the sensor was also fitted upside down.
Welcome to London where the roads belong to cyclists and pedestrians and motorists are a second thought. Only in london are pedestrians on walk for 3 minutes and cars on go for 3 seconds
Thanks again. There's no alarm monitoring just remote client access with the mobile app. So over all a good product and worth the money.
Thanks for you advice