Company Not Clear Full & Final & Other Benifit

No full and final settlement and no service required by the Firm. I was working in Cottage Industries Exposition Ltd. New Delhi for 24 years. I am graduated when joined the company. At the time of Covid-19, our service discontinues from April-20 to November -2020. The company requires our service from Sept-20 to February-21 for some days (03 days in a week) in a month. We have to work as company guideline. We have not received any benefit or salary during the covid-19 as per the Govt. rule. Sir now company discontinue our service and no intimation letter issued to us regarding service has been discontinuing, Sir company not given any salary receipt to the employee for last 10 Years, therefore, I have not to know exactly what is our basic salary as per government rule. No benefits were given to us as a Graduation label. I have not received the Relieving letter and Experience letter. Sir, can you suggest to me how to claim our full and final settlement as per the basic rule of government in the Graduation Label. My ESIC and EPF contribution has stop therefore I have to face a big problem with medical aid. I have 3 Child and my father is a senior citizen. They all depend on me. Sir, Please advise us. Dinesh Kumar