Denial of performance appraisal marks by the authorities

I am working in bank, My final performance appraisal marks for the year 2015-16 become '0' at that time I did not notice but in current year while checking my marks I came to know about it i raised the matter but management refuse to consider the matter as the time for raising grievance was 15 days from the date of final marks, othere is 3 tier process, 2 officers gave me marks ever higher official gave remark I agree but final mark is 0