Payment due

I run a small business ( advertising agency )in Bangalore ,most the my clients are real estate firm .I have multiple cases where my payment is due from. Very long time Case no 1 - an agency for whom we have worked and payment due is Rs 1 lakh when we said we will take legal action he repeatedly provokes us hey take legal action because he thinks with legal action i will be spending more than what I probably can get Case no .2 - Rs 2.5 lakh due on Vivansaa developer, Bangalore we have worked very hard as well as Invested our own money to promote their brand they even got business worth 5cr from our promotion it's been 2 yr we are still doing follow up to get our money Case no 3 - A big real estate firm like Sobha developer hasn't paid us from last 1.5 yr & when. I did research seems it's same case to many other vendor & I have no idea when they can initiate payment Case no.4 - Shriram properties very Reputed name here , denying the payment because their joint venture didnt work with other companies which has nothing to do with our work now they dnt rcv call, dnt respond to any mail All above case we have complete proof mails,work proof, purchase order & text of assurance M wondering how to close this issue if anyone can help plz do contact me [deleted]/[deleted]