What if fake data entry company sends legal notice?

Hello, I signed a contract with a company called WIXON INTERNATIONAL. They asked me to fill 500 forms with 90% accuracy in 5 days, promising a payment of ₹24,000 (after deducting a registration fee, I would receive ₹17,000). While working, I faced several issues and contacted them multiple times, but received no response via calls, messages, or emails. After 5 days, they sent a legal notice demanding payment, otherwise, I would have to go to court. I later found many people were scammed by similar companies, even after completing the work. Please help me understand what to do in this situation.