I am using a Spare Key to Drive My Car

I bought a Polo Vivo in March 2015 at Olgars Auto at Nigel, where they supp**** me with One Key which was a Spare key without Mobalizer. When i called them questioning them in regards of where abouts of the original key, they said they will post it to me. This has not happent in 5 Months now. When i called them again yesterday(16/07/2015) they said i must buy my own key which cost R3650. The Olgars Garage Manager's name is Irishad with No:*** and Sales Executive No:***. I really do not know what to do now because when its raining Heavy the car alarm comes off and when its windy too. when i open the car the alarm come off which i have to switch the ignition on to turn it off.