Did you submit notice of resignation, leave application in writing and do you have any acknowledgment?
Has the employer terminated your service in writing? Has the employer mentioned any reason of termination in the termination order?
The conduct of employer is bad and perturbing.
You are contemplating to contest the termination order or obtain payment of full and final settlement, FNF statement, service certificate, form 16,PF number/account slips, NOC/NDC, etc?
You may first of all submit a gentle representation in writing under acknowledgment addressed to your appointing authority, MD, Chairman, and narrate the total incidents and conclude that order of termination is bad and you have done nothing wrong by submitting leave application on the auspicious occasion of Raksha bandan and this should not have resulted into termination of service and now even after termination you are being tormented by stating that no service certificate, and FNF statement, full and final settlement, service certificate, form 16,PF number/account slips, NOC/NDC, etc shall be issued and supplied to you?
Let elders in the family, competent and experienced well wishers, lawyer draft and structure your letters so as to build some favorable record for you.
In a given situation employee can invoke the Industrial Employment standing orders Act, Payment of Wages Act, SE Act, and ID Act as per explanation of employee under these Enactments or approach civil court. Companies burn extra energy to convince employee that he/she is not a workman as many of the enactments favor employee and limit the choice to employer. However designation alone does not decide employee is a workman or not.
You may refer to SE act applicable to your state and approach Inspector/ALC. You are located in which state.
It shall be appropriate to show all documents to a competent and experienced service lawyer and proceed under expert advice.