1st discovery whether that person is the owner of the vehicle sold.
Whether you have got the vehicle transfer/purchase form signed.
These things are important to know before going legal and make out a case of fraud.
Adv Shailendra Dubey
You can send legal notice through your advocate and can claim paper of bike
If you want legal advise then you can call me on mobile no ,,9359867870
Advocate IRFAN SHAIKH