Hello, I was wondering if someone coul help me correcting this letter?

I am writing this letter to the president of /BFGW/, since from some time now I have been sent from one official to a second and the case still isn't solved.
I was hired in the factory 06/06/2005 as a drill operator.
01/06/2006 I was moved to the H sector, and after two weeks of training I started to operate the machines on my own, and that can be checked as I put my number on the orders.
In August 2008 I received a raise for a wage after two years of working, because like M.W. said there's nothing in contracts about wages after 2.5 years of seniority and that's how long I was working for then; which means half a year of my working time was cut in the factory.
In January 2009, as according to the contract I was supposed to get a wage of $22.95, and I still had $10.36, I wanted to clear that up. Unfortunately the changing supervisors weren't able to, or didn't want to help me with this situation.
In 06.2009 I got a raise to the wage of $22.95 which I was supposed to get in 01.2009, again unfortunately without evening out the period from January to June. Also, my seniority wasn't corrected and still it's half a year shorter than the factual one.
Therefore I got financial losses and losses as to my seniority which in present situation is equally important. I believe I'm a good worker and I treat my job seriously. If there's a need, I stay longer. It never happened that I wouldn't come to work without justification. In connection to that I expect to be treated seriously by the works.
I believe that this is only someone's oversight, which the president could help me explain.