Indian Postal Service — Registry letter not delivered

Address: Rewari, Haryana

Sir my PAN Card is not delivered to me. In records it shows delivered. Postman says I don't know. How can we tolerate this. Sir in past many letters were missing like my Aadhar card not delivered to me 4yrs after making. Many speed post n registerd letters were also missing.help me sir n I don't know how to handle this postman.
His name is Balwant n he is at post office Kund pin 123102. He always skip his duty n ran away. He never gave satisfactory reasons. Please be strict to him n help me to get my valuable documents back. I suffering from bank because they need PAN card to keep my account alive. Please help me n sue this postman.