KIA Rio's overheating

Bought a Kia Rio on 2018.02.03 by 07 December 18 car lost power drive straight to Eastvaal Motors Witbank since the car is there no progress report am the one phoning daily for it, the car never gave any sign on the temperature gauge or dials coming from a 30.000km service. The garage never trouble themselves to check wiring cause surely from the factory there is a problem cause it's 7 KIA with the same problem cause my friend drives one his too is there. Once u stripe a car for engineering to do measurements on the block that car for me it's death, second month paying for a car that's on the dealer who don't know what is what? Please people help