Did you try the following procedure to reset the tablet?
Note: Be aware that the following is a hard reset so doing this will erase all your data and downloaded apps (if any) installed in the tablet. It will restore the tablet to its factory default condition.
Hold down the Power button and the Volume Down button (both together) till the Chinese writing comes on.
Then navigate down using the Volume Down button to the 6th menu option i.e. 3rd from bottom.
Press the Power button to select it
If English script appears when pressing Power + Vol. Down:
Hold down Power button and Volume Down button (both together) till the Android icon with menu options appear.
Scroll down using the Vol. Down button to wipe data and press the Power button to select it.
Scroll down using the Vol. Down button to yes and press the Power to select.
It should reset. If it goes back to the menu options scroll to reboot and press the Power button.