Payment defaulter

I have to recieve payment of approx 6 lakh from a customer of mine which is a construction/plumbing contractor company . We did transaction well for two years and was smooth. But suddenly last year he stopped giving payment and buying material. From the last year in August till date he has made 2 lakh out of 8 lakhs approx. He doens't deny but don't even give payments . We have proof of supply in bills statement confirmation in mail and hard copy . C- form for the outstanding bills. Now we are doubt that he is unwilling to make payment and only giving us dates . Please suggest if any legal remedy exist for the same as we are afraid on spending money and time in courts.