I on a Paterson D3 level and earn R607k a year.  Three other people in my company are also on a D3 level but earn between R820-900k per year.  Is this allowed?  I am a top performer whilst they are not.  They are on a higher salary as they came into the company on a higher salary. 

I wonder if I am being discriminated against due to the fact that I don't have children?