Delay in payment of dues & Variable Pay

I have been working in a company based at pune as GM - Channel sales from August 14 till Feb 15 and it required me to shift from Noida to Pune to take this position . Due to sudden change of plan in Dec 14 , I was asked to resign from GM- Channel sales position by VP Strategy . This was on the behest Managing Director- UTS P Ltd. There was no rhyme and reason cited for asking resignation and it was completely handled unlawful. Inspite of this blatant misconduct by senior management, I resigned without creating any issue and on the condition in written by to clear my pending dues immediately. My umpteen mails since Feb 15 have not been responded. I have also written to investor of the company who is also director in the company. I have send registered letter to MD but till today there is no confirmation. My Long pending dues , over 7 month that these dues haven't been cleared and 4 months while in the company and 3 months post service. Since 19th Feb 2015, I have been following up in writing to company officials including MD but there is no professionalism/ courtesy even to respond single mail. ?? I have been harassed with their act and unlawfully holding of rightful dues. I have been writing to them since Feb 15 ( thru emails and registered letter) but till date no response and confirmation on when they will clear my dues. I want to send them notice for recovery of my rightful dues. pls suggest. rgds/Naveen