That model code would not show up on Google Search yesterday.
I tracked D2D in the UK. Its a Chimp electronics tablet, I would guess, either a 7" kids or 9" dual core.
http://www.chimpelectronics.com/tablets.html
There is no way to tell what hardware buttons it has (why I asked).
You can normally use a combination of button holds while powered off to bring up a Recovery Mode where you can chose to wipe data/factory reset with the volume key and select with a power key. (does it have a home button on the screen face as well?
Best to try to contact Chimp for Recovery mode (I know it's Christmas and it's a present etc).
It says there should be a leaflet enclosed, try there, but it may be basic.
Possibly someone better here can suggest what button options to try.
You may have solved this, or consigned it to the bin.
You get less responders over a holiday unfortunately.
You could also put your original post again in the Ask any Question forum, where you get a higher response rate in the late evening. I am also in the UK but most are not.
I hope you get it sorted for him.