Hyundai negligence

Good morning I purchased Nissan NP200 in November 2023 at Hyundai Springs. The car was over 21 0000KM on purchase, the car was only moving for local distances and It would park either at workplace or in the yard. The car was last driven in February 2024 and then it was parked. On the 26th of April 2024 the car was driven to Limpopo ( which is over 400KM), the car never reached home after being driven for over 300KM. The car jammed, wouldn't start the engine, they tried to jump start thinking it is the battery with no success, car pushed still no success. On the 27th of April the car was towed to Nissan Tzaneen where it was discovered that the engine was contaminated with sand particles, at Nissan they requested dekra report from where the car was purchased with no success. On the 10th of May I went to Hyundai springs to request the dekra report but instead i was given the report which was checking the dents and scratches and no dekra report was done before the car was sold. The dealer principal at Hyundai indicated that they will have a meeting with the managers to discuss the issue and they will get back to me on Monday ( 13th of May 2024) The diagnosis indicated that the engine has sand particles of which the pictures were sent to the dealer principal and the workshop manager via email. Hyundai has not gotten back to me till this day of which clearly state that the car was purchased with the fault which could not be observed earlier since the car was not moving. The car is not even 6 months old from the date of purchase. The car is currently at 23 000KM including the distance it moved to Limpopo before it broke down on its way