Hi victorm1
Are you sure that your TV model is 50UA3D83BD? I couldn't find a match for that device on my 360 so I googled that device for reviews and manuals and nothing came up in the search.
I did however find 50UA3D63DB using google search and entering 63DB as the device model number on the 360 brings up a match which works the channel and volume buttons.
Also on the 360, did you try the key testing method under Audio & Video > Pair remote with devices > TV devices?
Don't just accept the first one that appears to work. Try a few more as (like the older V6 and Tivo boxes) there are often 3 or 4 that will work, some more fully than others.