Correction in letter

please correct my letter

To
The principal

------------------

Sir/madam
I beg to state that I have joined this school since july 2007.commitment was from your side that what the salary was decided we will give you that much only .suppose they have decided 4000 but my demand was more then they told me but at last of the year according to the one month 1000 rs we will give you 12000 .every year we increase in your balance .like this year 1000 next year more increase like previous year 1000 next year may be 1100 or 1200.but only once time they have prpvide me 10 000rs
After that per month I am getting my salary but according to the commitment they have not clear my dues
According to 1000 one month 1000 12 months 12000
2007 to 2008 1year 12000
2008 to 2009 2 year 12000
2009 to 2010 3 year 12000
2010 to 2011 4 year 12000
48000
2011 to 2012 july 1000
August 1000
sep 1000
oct 1000
nov 1000
dec 1000
jan 1000
Feb 1000
8000
48000
8000
My total amount 56000
In first year they have provide me 10 000
So total amount balance 46 000
According to commitment should be more
Like one year 12000
next year more increment
salary I am getting as all the teacher s
but they are not going to clear my dues
my dues should be clear and from next month 1000 rs should be attach in my salary.
I donot want to take at the end of the year
1 year 12 casual leave
4 year 48
It should be cash
Because every year they used to say that we will cash your causal leave
But they are not providing
Yours sincerely
Xy z

Please correct my letter and where you want to add from your side any sentence you can
Give the correct shape of my letter