Why the words "Demo" are always displaying on the screen in Red Color for AUXUS AX04?

[AC Question]

The word "Demo" are always displaying on the screen of AUXUS AX04 Tablet which was purchased from ebay in Mid 2014. I tried to reset to the factory restore...but it is not doing any thing. I have updated Android Kitkat 4.4.2. but still the problem persists even after scanning with Antivirus software..Plz. suggest how to rectify this to get normal screen.

 

[jasonandrews25788]

I think it's a demo version of the device meant to be for a show or something. however, can you upload a screenshot?