Thank you to all for your imput. Thank you LUKESKYWAITER for your kind offer !! Thank you for blocking out my personal info .I just did not think when I posted . I have written a further letter to the CO address which I will add here . I have not heard a thing. When I booked this flight I was waitlisted for an upgrade using miles which did not clear I guess. I was traveling on a N class tix and was never given a different boarding pass Just sent to the window seat by the gate agent. There were the small bottles of champagne on the flight as I had asked for and almost had been served one while in my seat 1B so close and yet.The GA told me that the FA was apprised of the situation my down grade which I took that at face value...My real question is are seats being sold after the departure time of the flight even if it is delayed? Seems strange. I do hope to hear from CO regarding my follow up soon. I do not think I will move again if the circumstance repeats itself...

Dear CO CS,
I thank you for your reply. I am disappointed to know that after the departure time of the flight a seat could be sold at the gate counter I am assuming?? that would require a platinum customer already seated in the plane? to be resented and in a window seat as there was limited availability am amazed that I had put my miles against an upgrade when I bought my seats and still was bounced out of a seat I had been issued a boarding pass on? I am assuming I am just not that important in the larger scheme of things. Sadly disappointed
Jane T Lee

Jane Lee