Highly Annoyed

I purchased a BMW in March 2014 and since, have been experiencing instability with my car. My BMW has been to the Cresta workshop 3 times and on every occasion I am told my Rims are bucked, fix it for a smooth drive (Last advised this in Nov 2014) My car was sent to the Dealer where I bought the car from and they advised me that the bucked rims were fixed, I then had my tyres changed. Still, I am unsafe every time I drive this car. With no urgency when I advise BMW what my car does and I need to book it in, they still lightly fit me in when they can. My car is at the dealer now and the technician advised me this morning that my car is fine. I insisted that it is not and want a proper check, Now it is picked up that my car was apparently bumped at the back and this has bent my trailing arms and my rims are still buckled hence my car is a disaster on the road. Firstly, why was this not picked up on the first visit to BMW, I have driven for months terrified? secondly, why does my BMW motor plan not cover this? 3rdly my car will be kept over at BMW and BMW never has courtesy vehicles for their customers. What a damn joke. I will never recommend BMW to anyone! I have had no joy with BMW