Can a dealer sign a contract for me ?

I lease a car in 2015, I left the dealer with a new car and a contract with me. 3 years later I am about to return the car but the finance company told me that they have a different contract that the one a signed 3 years ago. I ask them to send me a copy of the contract by mail, I received the contract but is not my signature. I contact the dealer to prove that I sign this contract but they can't fiend it. I'll try to call the dealer many times and they are just ignoring me. Is anything I can do?