As I have said, I don't think it is asking much to have the unit swapped out, I am willing to ship it back but you won't swap it out.
This unit clearly has no front end protection and that is a design fault, if equipment is not of merchantable quality and is going to keep on failing with the same problem then I believe I am entitled to a refund, I have already accepted one repair (took weeks) and the unit now exhibits the same fault a few months on. As I said in my emails, I had planned to take the unit on vacation at the end of this week and you will not swap the unit, why?
One other option would be to tell me which part has most likely failed, first semiconductor device I presume, and I'll change it myself, I have surface mount rework kit and this is clearly going to be an ongoing problem.