getting my car

I live in Toronto.I sent money to my cousin to buy me a car in Georgia.The car was bought and brought to me by him in Toronto.A year later I sent back the car to him because the tag was expiring.After the tag was renewed my sister who also lives in Georgia  asked to used the car for a couple months before its sent back to me.When the time reached for her to return the car,she refused and has been threatening my cousin should he try to take back the car.My cousin brother too is afraid of her and doesn't want to be confrontational.He has sent me the car title and a bill of sale.How do I go about getting the car back.