Car not fixed and parts still on order

I drive a Ford Ikon 1, 6. The car was received in December 2014. At 200km she developed a misfire at idle. The car went in 3x before it had a sensor replaced. The vehicle now has 3800km and the misfire now occurs at startup and the car has a very uneven idle when hot. The B post covers on the LHS have been on order since February. Ford, your vehicles have come along way in 5 years, but if the dealership cannot fix them what good are they. My second vehicle, a Focus has similar issues, and for a 2013 model its not good. The general attitude from your servicing dealers are they will get back to me, they never do. Thus, the vehicle has both warranty and a maintenance plan. My car has been in 9 times since purchase. If the motor fails due to incorrect fuel ratios, misfire deterioration or other manufacturer concern, I assume that since I have been in 9x you will honour the warranty and replace it.As a client I should not have to call Iin every two weeks to check whether you have parts or whether we can schedule the vehicle for diagnosis, that should be a service you offer as part and parcel of buying a vehicle. The left rear door has to be slammed to close and I get told that the car