My son's tablet is less than 4 months old and it keeps shutting off even when fully charged. It is a 9 inch nextbook and was purchased at Walmart.

Hello, Bridget -

If you have had your Nextbook for a while, the rechargeable battery may no longer be holding a charge.

Even rechargeable batteries wear out and need to be replaced.

You can probably find the right replacement battery (for your Nextbook model) to purchase through the Nextbook home page.

Is the back removable or does the NextBook get hot?

It should still be under warranty. If you lost the receipt, large stores like Target or Walmart can print another and even help you with warranty info. It might be worth a try.

hook it to computer and go to the kurio site and have them diagnose it or they will send you a box to send it to them to be fixed or replaced,tell them its less than 9 months old

send it for warranty repair

All I can suggest, as you are doing , keep trying to contact service provider , as your problem need their help. Is their a RE SET button on the unit.

Almost everyone knows who makes the best..... Not that any brand is perfect. But people still persist in buying the cheapest. I know this doesn't help your current predicament... but you have to think before you buy! I've had 3 iPads now and none have had anything like what your describing.
Good Luck in with your future purchases.