Hello.:-D
For your reference:
http://salarylettersamples.blogspot.jp/2012_10_01_archive.html
(I don't know if they are good or not. Try writing your own letter. Good luck!)
You can get help if you make some effort first. I am sure you could write this letter in your own language so do that first and then try to translate it as well as you can into English.
"In my appraisal interview ten months ago, I was told that I would receive 24000 of bonus amount based on performance. But our HR says that I'm not eligible as I'm relieving from the services of company before the completion of year(October 2013 - September 2014, He considered from the salary revised date).
I got to know from my sources that one of employee who relieved company received full bonus amount even with out completion of year at the time of relieving. This makes me feel like I'm being discriminated.
I have worked with your organization for the last two years as junior systems analyst with dedication at work and I have completed all the assignments with in deadline and my attitude in dealing with colleagues and superiors was excellent. I have impressed our clients with my work. So I strongly believe that I definitely deserve the bonus & I have asked same.
I didn't get why I have been discriminated so though I worked for the interest and growth of company.
I hope you will take a favorable view in recognizing my earnest contributions to the company.
Thank you and hoping for a positive response from you."
Please take a review on the above draft letter.