HTC — HTC Desire 816- Faulty handset

I have purchase Htc desire 816 in the month of dec 2015. In the 3rd month after purchase, i was facing problem with the side button, when it was send to the service center they told some software update was done, and it will work fine. Now, some 25 days back while i was talking over the phone, suddenly phone got black out, again it was send to service center.(Sri Sai Communication, Secunderabad). They told it need to be send to Delhi, their head service office. (Here, i came to know its just collection center, they dont do service but still its called serivice center). When it went to Delhi, they told its a liquid damage and for service they asked nearly Rs 7000. I told them liquid damage is not possible as no water entered into the phone. And i asked them to send images where it shows its a liquid damage like some ink blot. They gave all lame excuses for the damage like moisture, sweating. In a sealed phone all such reasons are lame excuse, just for the sake of not covering the phone under warranty and charging their customer high. This went for a week, but i dint get any images from their end and today they told they have send the phone back without repairing it. This show HTC as a brand and their worst customer care.