Address your final communication to good offices of appointing authority, MD, Chairman and cite clauses of appointment letter on NO Notice period, and handover of all assets (attach acknowledgment), unblemished service/rewards/awards etc and narrate all representations made so far by email/phone calls/letters/in person (mention names/dates etc) and ask to supply salary slip of all months, Pf number, Pf a/c slips issued by EPFO, acceptance of resignation, FnF statement,FnF wages,Form16, servcie certificate, relieving letter, NOC/NDC etc.....
The above are suggestions only and you may take help of employee's/trade union leaders, labor Law consultant to draft your representations.
If you are covered by the def. of 'Employee' as In Delhi Shops & Estbs Act (ask your counsel to handle the clause on notice period 30 days as per 1 year of service by citing from appointment letter that employer on its won provided better service conditions or avoid agitation under this Act), 'Workman' as in ID Act then you may approach:
Inspector appointed under DelhiShops & Estbs Act, Payment of wages Act,O/o Labor Commissioner
Your counsels may opine that you can lodge complaint u/s 406,420, winding up petition, Civil suit for recovery/damages, etc
Your counsel would know how to send legal notice.
Have you consulted a counsel at Delhi?