How to get F&F from my previous employer

HI, I had resigned from my previous employer having their HO at Mumbai on 8th May"2017 with a notice for 30 days which is 7th June"2017,as par the terms of my employment of serving 1 month notice period. I received an acknowledgement mail from HR regarding the acceptance of my resignation and release from my duties as on 31st May"2017 itself. Afterwards I had submitted all the necessary documents and NOCs from all my dealers in the month of August"2017 and received an acknowledgement mail from admin dept regarding the same on 7th Sep2017. I had worked in the company for 5 yrs and 1 month, hence eligible for gratuity.Beside that my notice period salary,two months field expenses, bonus for the year,a small amount of marketing expense and leave encasement are due from the company. I am yet to get my F&F from the company even after repeated follow-ups on mail and telephone. Every time they are just citing one or the other excuses and lingering the payment yet.. Its been 9 months from my last day of working and almost 6 months from the date of submission of necessary documents. Kindly suggest what kind legal procedures should I adopt to recover my dues with the company.IS there any other procedures beside legal means. Thanks & Regards Amar