Nissan Magnite full of faults

I am so disappointed with Nissan SA, I have been complaining to the dealer in Mthatha about problems I'm facing with the Nissan Magnite but they are failing to find causes and solutions. On the 17 July the car was not starting it had to be towed to the dealer bt they don't know the cause, it showed a warning that Tyre sensor is not working but they could not explain what it means or the cause. On the 22 July it locked passenger doors to an extent my daughter got out thru drivers door. Today on the 26 July it's not starting again and it's showing same sign Tyre sensor not working and it's not starting. I have been requesting Nissan to take back its car but they do not want to account that their car has faults since it was four months old I've been experiencing same problems up to date. I am not enjoying it at all because it's fine only for a week following week its towed and I have to use public transport.