Paying two cars but have one car

2023 December me and my wife went to motus vereneeging as renault kiger that we bought gave us a problem then we went there, they referred us to sales advisors then the advisor said they can change the car then they change the car now 2026 we want to do trade in they telling us we have a short fall of 350 000 all this years it means we wer paying for the car we returned we haven't get to the one they exchanged for us