FAULTY VEHICLE (2015 FOCUS ST1)

I took delivery of my new Ford Focus st-1 on the 2nd of November 2015. After around 10 days i noticed that the car was trying to stall itself when coming to a halt with the revs dropping to 500 rpm and below.Clearly my problem has been noted the year before from ford as per the link. [URL Removed] Exactly to weeks after i took delivery i drove that vehicle back to the Dealership asking them why the car did this. To cut a long story short. They have attempted to fix the car 2 times already and not succeeding once. I have only had the dealer principle call me once when he agreed we can get ford head office involved to start the process of a vehicle exchange. Since then i have heard nothing as to when this will take place as my last email was sent on the 13th of January 2016 requesting feedback on this matter. I will never purchase another Ford in my life as the quality seems to inferior. Now i am sitting with a faulty vehicle.