Kamvas 16 display issues (Greyscale and black bars)

The tablet works fine as it should be.  But the bottom half of the screen fades into complete greyscale, with a black bar along the bottom that will grow anywhere from a quarter inch to a full inch in size as I use it.  Though despite those glitches I can still click things. Buying a new cord hasn't fixed it, this has been an issue for months and the tickets that were sent in directly (By the person who gifted me the tablet and has all of the order information) in the past have not been answered.