Poor mileage performance

I bought my MG Hector Sharp DCT last month and I travelled around 27kms today and the mileage I observed is less than 6kmpl which is very far less than what was committed i.e., 9kmpl in city and 12kmpl on highway. This is really the worst performance in terms of mileage in any car I have driven so far. With this kind of result, I am forced to believe that the commitment and the claims made by the company are all false.