Car fraud case

So the story begins from 2016. Mr. A sold his car to Mr. B for 7L. On the installment basis. Here there was mediator Mr. C. Mr. B gave 4L. That also by saying I'll give you the amount but I don't have much right now I'll pay you soon. Mr. A was very lenient and gave him the time. In 2018 he said he has applied for loan as soon as it get sanctioned he will pay.In Aug 2020 finally Mr. B said that his loan has sanctioned he give the money in 10 days But after that Mr. B Never picked the call. In September 2020 Mr. A got a call from Mr. D that he has bought the same car from Mr. E where as there was no relation between Mr. D and Mr. E. And the car owner is still on the name of Mr. A