Interior startup is not returning the unused amount as we discontinued

I have hired an interior designer company for my apartment. They promised to do a good job in minimal cost and were saying they were not looking to make money, but looking to create a good portfolio. They hired a freelance designer (who has a day job) in another design firm. She was not very helpful during the design phase. It took us 3 months with lot of our efforts to get a decent output from her. They weren’t able to monitor / get good output from her. We have paid 50k as advance amount for design phase. Meanwhile, I have asked them to start False ceiling work and paid 1 lac amount to them. Initially, they told they have two factories owned by brothers, and promised 7 years warranty. But, they do not have any factories, they are just hiring carpenters from these factories and acting as middle men here. They have not even provided any physical agreement, but shared a soft copy of agreement over WhatsApp. As, we did not want to risk the money with them for the rest of wood work. We told them, we are discontinuing their service. They are now not responding about the money to be returned apart from the work done. they are withholding at least 40-50k. I have requested them multiple times over phone / messages and email to resolve this. But , they are not responding. please suggest what can be done. PS: I have now hired another company and started design phase and planning again. It has been 10 days since, I told the previous company we do not want to proceed.