Amount paid but project not delivered

Hi, We have agreed with one agency to create web application with fixed budget method. We don't have any legal agreements. But we have emails and whatapp discussion of them. As part of that they started working on designs in 2015. But we both have spent lot of time on designs because they didn't met our expectations. So we stopped working and told them that we will get back you once we clear with this design issue. However we have paid amount fully through our bank to their current account. Now in 2019 we have came with different idea or plan for different application. We have sent designs of new project to them now in 2019 as mentioned to them earlier. They said that its it's difficult to work on these designs. You please hire some other agency for design part and rest we will take care. As discussed we have discussed with some designs agency and they agreed to work on designs. We have informed this to the original agency and asked their response. I have been waited more than a week for their response to continue with design part with other agency. But now they are saying that we can't deliver this to you. When we started in 2015. We are different and now we have transformed to completely new industry and they are also saying that the person which took your project is no longer with us. So I asked refund of my amount after deducting design charges for their work on earlier one. Which is around 120k rupees. But I have paid them close to 400k. Now they are refusing to refund and also working on this. They are saying that we have worked very long on your earlier project on design part and whatever we have paid is enough to that. We want legal option on this. Please do needful. Thank you Ajay.