Employer refused paying satisfactory amount of salary

I was hired as a freelance content writer after a month long Internship at F Salon Academy India(A Fashion TV venture) on 17-03-20, I worked at the firm till 03-06-20. My role at the firm was to create content for website and later to mentor the content writing team and create content with them. At 03-06-20 the employer called me and said that due to lock down he will not be able to offer me a paid job and I can continue unpaid if I want to to which I refused, when asked for the payment of previous dues I was said the I will be paid only for the content that I wrote as an Individual writer and that too according to whatever portion of my content they use in their website and I will not receive any payment for mentor-ship because that according to them was given to me as a experience gaining opportunity. My point here is that I made it very clear before the start of my freelancing term that I would not like to continue doing any sort of unpaid work and that was the reason of my transfer from internship to freelancing, despite that I was made to do free work which I was not aware that they were not willing to pay until I asked for payment also all my content that I delivered as a Individual writer was verified by the employer and did perfectly met their requirements and thus usage of my content lies in their hands and I should be paid for my whole content and not just the portion of it they use. Please guide me on how I should proceed with this matter