What legal action recovers unpaid house down payment from corporator?

I invested ₹8 lakhs in cash as a down payment for a house through a corporator, as the property belonged to his relative and he was handling the deal. Due to registration issues, the deal was delayed, so I decided to redirect the money elsewhere. Despite repeated follow-ups, the corporator has returned only ₹1.25 lakhs over a year. I’m concerned that if I stop following up, he will never repay the remaining amount, as he seems indifferent. Please advise what legal action I can take to compel him to return the money and ensure he takes this matter seriously due to legal consequences.