It is kind of ironic that back about nine years ago I went through a somewhat similar experience with Toshiba with a large screen RPCRT that I had purchased a few months prior(those were the days of 3 year warranties) in that there were differing opinions on a problem which was, over the course of several weeks and several phone calls getting me nowhere, so I took someone's advice, summarized the issues, the timelines, stated I would be reluctant ever again to buy one of his products, then, wrote a letter addressed directly to the President of Toshiba.
Within days, I got a call from the service department which was arranging for a time that they could deliver my new monitor and set it up for me. I still have it and it is working beautifully.
I learned a lesson from this and another situation I ran in to with Sears in that essentially what happens if the problem is not reaching a conclusion and you are probably entitled to a replacement, generally speaking, people at the service or sales department level or equivalent are not high up enough the ladder to authorize much of anything. You have to go right to the top to at least have a better chance of getting the results you are looking for.