Factory Fault on the locking system of my car boot

I bought a Micra 2014 at Hatfield branch and within 3 months the boot could no longer lock, therefore affecting all other doors not to lock. I then took it to the nearest branch at Nissan Middelburg whereby it was fixed but withing two months it could not lock again. That indicated to me that they just did a temporary fix not the proper one. Meanwhile as I open and close the boot, it caused the windscreen at the back of the boot to smash into pieces. I reported the windscreen to my insurance because I could not drive the car in that condition, which my insurance took care of the windscreen damage but I was informed to pay access money, which for some reason, the repairers did not claim from me until now but I am not sure if I am cleared from the debt. I reported the issue again to the Middelburg branch and I was promised that the part will be orderd within a week which never happened and kept following up with empty promises. Now it is two years trying to fix the lock of the boot and all this time I park and drive my car unlocked. What is shcoking is that during Dec one guy opened the front passenger door trying to ***** my phone from the charger & the door shall easily open