Mmrda Scomi Utpl - Non payment of gratuity

Employees who worked under scomi utpl a Malaysian company for MMRDA Mumbai monorail after five years mmrda terminated SCOMI and appointed DS company. They are now not taking our responsibility of paying gratuity and only current employees are assured of gratuity. Scomi has subdivision company in Borivali which is their oil division which is their registered office mentioned in our resignation letter. When we go there they deny us entry by saying they are not responsible as they are in the oil division.
We feel cheated how did scomi leave India so early without clearing our dues. Why mmrda and subdivision office of scomi not taking our responsibility.
Why Employees who are with newly appointed DS Company by MMRDA taking responsibility of employees working now and not us as they are creating a rift between employees. Please help us.