I have problem with Nissan Morgan garage at Lydenburg

I have problem with Nissan Morgan garage at Lydenburg. They refuse to fix my car almost is three months for now and this car it still under warranty and motor plan , last week they call me to come and fetch my car suddenly I found that they s****ped the engine while they treated me to charge the storage if I’m not coming and I was with the towing car that I pay almost 5k.so please help me to get my car fixed