A/C went out shortly after car bought new from dealership

AC computer chip went out and it was connected to the engine so car turned itself off, had to tow it! Cost me 300.00$, its also connected to the climate controller system so still have no defrost or AC. Mechanic said would cost to replace chip, $1200.00. So, of course still not fixed. Had to have mechanic bypass the engine so the car would run again!!! Hyundia refused to help fix again!!!