Wrong Transfer by the Seller to the Non-Confirmed Purchaser

I had seen a Scooty pep on OLX which the seller to collect it on 4th Feb-2017. When I went to his home with money and sale deed duly signed by my wife with xerox of voter ID , they refused to hand over the vehicle and said that first they would transfer to vehicle in my wife's name and then would give me. Without any payment and vehicle I returned but handed over the sale deed to them duly signed by my wife as buyer. In the meatime they asked for my wife's photo which I sent through mail. On 6th March I was informed by the seller to come and collect the vehicle as the transfer has been processed. On 19th March , during my paper verification , I found the RC missing. On asking the seller and his mother both said that transfer is still in process and I should take the vehicle without any problem. I refused to take the vehicle right then without the RC . I posted my refusal to be unable to purchase their vehicle for misinformation and lack of money happened due to unforeseen circumstances in my family on OLX also the next day i.e. 20th March which the seller read just 1 hour of my posting same and I have proof of it, On 13/4/17 late evening I received a sudden call from the seller that the vehicle has been transferred in my wife's name. After checking from UPRTO they were correct. When the same was informed yesterday , the seller threatened of dire consequences. As I had already refused the purchase , where am I at fault as well as how should I prevent my wife from wrong indictment in all this before the court of Law.