Dont buy a car from these people

We bought a car at the beginning of august from eae motors in verenigingin the contract you sign it says that if any faults occur in the first 30 days or 1000kms they will repair or exchange the defective part. The day after we took delivery of the car the engine light came on so we took it back and they said it was a sensor that they fixed. it then happened 3 more times with the same sensor being at fault. When i told them that the problem is still happening they told me that they are not fixing it and wont tell me why, also that i should use the warranty i bought with the car to fix something they are responsible for. Do not buy from these people they will tell you that they will sort out any problems but they WONT.