I need legal advice for Issue

I get instruction from Mr X to look for a Toyatto car in hafar al batin, I searched and suggest a car, he told me to do engine inspection after that he agreed to purchase the car and transfer 20000 sar to the showroom and remaining to me. Once I went to deliver the car to Al Jubail, he was not willing to accept the car and told me to return back to the showroom. I return the car to the showroom. Now Mr X formed a case on me that Mr X sold the car to me. And request to transfer the ownership to me. He threaded me that he will kill my family in india.