promotion granted while monetary benefit not granted.

I am an employee of Directorate of Factories, Govt. of W. B. Labour Department, have been promoted from the post of Scrutiny Assistant to Statistical Assistant without any monetary benefit (same grade pay 3600/-) in statistical Section since 2014. While my juniors are enjoying grade pay of 3900/- in the post of Head Clerk from the post of U.D.A. in general section in the same office. Whether I am eligible for getting pay protection or any monetary benefit?