Worst services and experience of my life

The worst experience I have ever had. I traded in my car for another. I've had multiple different issues from the purchase date. The last issue regarding my park pilot where one of the sensors is faulty (NOTE: only after they repaired a small dent next to the sensor) has still not been fixed. The previous time I took the car into them they assured me that the problem is resolved however the problem is still there. To top it off - it has now been nearly a year and then I received a toll gate account for my old car! They assured me that my old car will not leave the lot with my personalized number plate just for me to receive this! Horrible! I contacted the salesperson and asked him to confirm that I will no longer be getting any toll accounts/fines from my old vehicle. After asking again to confirm it in an email I got a very unprofessional "Kort af" email! Highly dissatisfied!