The Mk IV Golf (two generations ago) had this problem that gained some notoriety on BBC Watchdog and I proposed a solution to VW that had worked in my Mk II. First switch the vents to recirculate. Then turn the heater to max heat. Then direct all unclosable vents to the footwell. Then close all closable vents. That minimises air disturbances inside the car, which are usually what sets the alarm off. Your rights in English and Scottish law are against the supplier, not the manufacturer.