Make sure you are in the right place
The most important thing is to make sure you are in the right place rather than a third class organisation. Good companies have an independent HR department, which deals with various issues related to the employee.
Identify your problem
Next thing is to find out what the problem actually is. Once you have done that, then is the right time to move forward.
Another important thing is to keep your cool. If you cannot control your temperament, the other person might end up taking advantage of that.
Start composing the email
Now is the time to start writing the email to the concerned department.
Use a professional tone
Make sure that you are using a thoroughly professional tone in the email, as it will give a good impression to the HR department.
Wait for action by the concerned personnel
Finally, wait for the reply from the concerned department and don’t send them any reminders repeatedly.