how to recover due after providing services to company

I provided marketing services to a company in gurgaon which own audi gurgaon and audi delhi central showroom dealership. This company terminated the contract in august 2013 without any notice and assured us for the due payment very soon. I kept following them via email, personal meeting and also via phone but they did not entertain me or my request. Their assistant manager always spoke lies via email and also avoided us. Let me know what all I can I do legally against this company and its manager. Also how can I get my payment back?