Purchased a brand new 7inch telefinken tablet for my son

Purchased a brand new 7inch telefinken tablet for my son. Tablet keeps shutting down on its own definitely a software issue. This is for school use daily i dont have time to wait 7/21days to repair etc my child needs a new tablet . I cannot keep him at home for 21days. I need a full refund so i can go purchase another brand tablet at another store!!! Thank you.