Car Trailer Purchase

I bought a Car Trailer from a gentleman in Johannesburg East without the registration certificate [BOOK], little did i know that he sold this trailer because he was frustrated. He had not been given the papers from the original owner. When i asked about the papers he told me he will get them in a week's time. This did not happen, but he sends me the conversations he had done with the original owner of the trailer, and the person who had been tasked to organize the papers. I tried to communicate with the original owner and the gentleman who was organizing the papers, but to no avail. They actually blocked me, and any further communication was to no avail. I have the WhatsApp massages that i can forward to you. Your assistance to this will be greatly appreciated. I need the trailer papers.