LG Electronics — AC not working

LG AC wasnt working so the technician changed the motor and charged me 3500 Rs after which the AC did not work, then he took all the parts and fixed our AC after which the AC again did not work, now he is saying the PCB is damaged, he is asking me to pay again. This is completely wrong from the company's end. Now if I pay 4000 again what is the guarantee that the AC will work. I want this to be resolved immediately. Very poor service from LG. I have been calling customer care but no body has any solution.