GD Motors Nalapara Guwahati - Complain under sectionof the consumer protection Act 2019

Respected Sir,
I purchased an Eicher Pro **** XP Plus **ft vehicle (Registration No: AS **S C****, Model No. ****) from GD Motors, an authorized Eicher dealership in Nalapara, Guwahati, on February *, ****. The dealership’s CSM, Uditanshu Parida, and agent Osman Ali assured me that the vehicle would deliver a mileage of *-* km per litre. They also promised that if the vehicle failed to achieve this mileage, they would replace it, provide necessary servicing, or refund the payment. However, after starting to use the vehicle, I was shocked to find that it only delivers a mileage of *.*-*.* km per litre.
Sir, I sold my previous vehicle to afford the EMI for this one, but due to the high fuel costs and other expenses, I am unable to save anything. I am forced to pay the EMI from my own pocket. Despite repeatedly raising complaints at the Eicher Service Centre at GD Motors in Barpeta, Howly, no action has been taken to address the issue.
I humbly request you to kindly take action and arrange for either a replacement of the vehicle or a full refund so that I can avoid further financial losses.