Harrasement by a technician

Sir/Madam, i have repaired my fridge few days ago by atechnician. i have paid him the money without taking any cash memo from him. now after bringing back the fridge i find that it is not repaired fully & i called him &even visited his shop to inform him. but he didnt came. seeing all this mostly his evil intension i have recorded a video where he declared that he has done the repairment job. i can prove that he has done this work. now i want to file a case against him. Kindly suggest me how can i file a case against him & what r the procedures. i have no cash memo to show court that he has done this work,just a video. kindly suggest. Thanks.