unsatisfactory of the vehicle promised by the company employees

I bought mahindra maximo the vehicle is not up to the mark
They said it has been improved bs 4 plus with the mileage good ….but I am very unhappy with this vehicle and I bought this in mahindra finance another big mistake ….is there any options to change the vehicle ? Even I get mahindra vetro I am happy if you get me good prize it would be greatfull