Times Global Assurance - Wrongly charged for mobile insurance

I had approached Times Global Assurance for my iPhone X insurance. They first make you pay online so I paid Rs. ****/-. Then they asked me for my documents, which I provided. During this time they confirmed that if they reject my insurance they will give me a refund within a few days. Before I got my insurance my phone met with an accident. So I approached them and told them about it immediately. They said they can't process the insurance anymore but they will process the refund. I kept writing to them and they said **-** days without any clarity and finally stopped replying.
Finally, I wrote to them if the refund is not processed then I will file a complaint and their response was because of "your threat" we will not refund your money anymore. They have wrongfully kept my money. This has been a highly stressful situation and they are blatantly stealing my money. From my phone interaction with them, it seems like this company is run by a single person or a couple of people. They did not seem like professionals. Even their emails seemed ill-constructed and misleading with no direct information.
During this debacle, I read a lot of online reviews saying they are a fake company cheating people and stealing their original phone parts and replacing them with fake ones. And also about them not refunding to a lot of people.