Central Board Of Secondary Education [CBSE] — Class 12th marks

As per cbse, the result of 12th is calculated by 30-30-40 formula, which is 30% marks from class 10th and class 11th and 40% marks from class 12th midterms and preboard, but in my school "the new era public School campus 2 " the evaluation of marks is done from some different and sense-less evaluation criteria.
This is total injustice with the students who secure a decent score in 11th and 12th pre board .The marks are given by total partiality and the school gave importance only to their old students.and those are whom going to teacher coaching institute
I beg to CBSE please give justice as soon as possible .
Thanks.

Roll no - ( protected)
School code - 50379