Salary due from 3months from Pvt company


I was working for a Pvt garment company in bangalore as a Factory manager. I had resigned due to my personal problems during my resignation there was a salary due for 3months. I completed all the formalities and joined another company in abroad.
When I resigned the company told that they will clear my dues within a month but now its almost 6months passed they are not responding to mail requests.
Then I Send my friend as my family had commitment.they are blaming and finding reasons like I have made a loss to the company so we r not paying him. I have not done anything like that and moreover the c9mpany was I had finance condition, this was a reason I changed my job. Now I want to recover my dues legally. I need you advise some of my friends suggested me to write to PM office to get the salary due back is that what I should do . Kindly advise