Is the issue happening before or after you install apps and files? If it is after, it may be an issue with something installed. Just a theory. Will it load up (although gives restricted access) in "Safe Mode"? If yes, then there is probably something on it. If not, then I would keep contacting the manufacturer about it so you can get them to give you a different device. Not just a new version of the same one. Different model perhaps.
To get into "Safe Mode" please do the following.
1. First turn off the tablet.
2. Next press and hold "Power" until you see the manufacturers logo on the screen, then release the power button.
3. "Quickly" press "Volume Down" and hold it for few seconds until you see the message "Safe mode: ON" or something similar.
4. If you wanted disable it, simply repeat the steps above, and you should see "Safe Mode: OFF" rather than on.