Sony India — Sony bravia tv model no: klv - 37s550a, serial no: 6150882, purchased in 2009

Address:

Gautam Buddh Nagar, Uttar Pradesh

I purchased this "Pathetic Model" in october 2009 and since then i have spend around 30k to keep it running. Another 9K in waiting.
After two years of purchase the motherboard was changed for 8-9K and last september entire panel was changed for 16k or something.
Now again there is no display. Sony engineer visited my premises and told that motherboard need to be changed that would cost me another 9K. I told him that Panel was changed few months back so it must be under warranty but he said that motherboard is faulty.
According to sony India motherboard is not in production so they offered me mere 25% discount on a new Sony TV which is not justified.
Why will i shell 50k? Please help resolve the matter as they should provide me a new set free of cost.