LG Electronics — Poor quality microwaves

I am having an extremely bad experience with LG microwave. We had purchased it thinking it is the best quality but it seems it is no longer true. Our microwave stopped working after an year. they replaced the magnetron. The real story starts here Our microwave has stopped working like it did earlier...it does not cook at all....if kept ON for more than 12-15 mins there is no heating at all....it seems they have replaced with a defective magnetron or a third quality magnetron...despite calling the service guys multiple times they refuse to agree there is a problem as they would have to admit their scam. Please be advised against buying LG microwaves...I guess this must be true of all their products