Firstly, the company followed unfair labour practice by asking you to resign. If the company wanted to reduce its staff, it should have retrenched you as per law and pay the full and final along with the retrenchment letter instead of asking you to resign, which amounts to forcible resignation. 

That is the way prescribed under the law for retrenching the staff. Any how, now your grievance is limited only to receive the full and final settlement amount and if the employer is refusing it on frivolous grounds, you may file a complaint before the Assistant Labour Commissioner of your area. 

The Assistant Labour Commissioner will initiate conciliation proceedings and call the H.R. Department Head to his office and in your presence, he will ensure that the employer pays your final settlement. If any small amount is the bone of contention, that can be reduced out of your full and final settlement and that amount should not be a reason for them to refuse you the final amount altogether.