Replacement engine

I got a breakdown with my car last year november i towed my car to AAA recovery since they were refferd by insurance.the qouted 37000 to replace my engine warranty was supposed to pay 20000 after the work is done.i paid 17000 to AAA n collected the car the guy ddnt wanna show or give me old engine there was no papers of a new engine the engine number on the invoice was still old one. I took the car early feb.the car wa mis firing i notifyd the mechanic 30min after i pick up the car cause it ddnt have power.called insurence to stop the out standing payment of 20.000 the guy ddnt replace my engine he just fixed the old one n quated for a replacement engine till now i dont have a car with me can hellopeter help me on that.