Full and Final Settlement

I worked for a company for almost 7years based in Bangalore and HO in Chennai. As DGM - Sales managing team members Last year June they offered me to move to Chennai as they are closing Bangalore operations but I denied due to personal reasons, I supported them building Inside Sales team in Chennai I continued working as Work from Home and In September they told will slash salary by 40% due to non-performance as Individual. Previously I never had individual targets such at the same time Q2 is always non-performing months for us. I declined to accept the salary slash and they told to resign with no option I resigned on 12th sept but they did not let me to serve the notice period and relived me on 21st September. Post which they did settlement in November with huge deductions and calculated salary based on basics which were total of 1.44lacs as per calculations I was supposed to receive 1.85lacs including the gratuity. I agreed and signed to F&F letter but received the credit of 1.21lacs only. They gave some lame reasons again. Now I need your advice to get the salary due and also the sales incentives for the year of 2016 to 2017(financial year) which was supposed to be paid I August 2017. Also if there is an option to severance salary for not letting to me serve the notice period.