DELL XPS 15 Problems

SAME PROBLEM
- computer repeatedly doesn’t turn on, shuts back of
WON’T TURN ON
screen randomly goes all pixelated in the 5mm flashing squares and then turns off, or sometimes just shots off in a different way
- the computer worked for about a day and it started happening
- happened 3 times in the span of 15 minutes
They said they would want to try replacing the battery last time but they sent it back without doing that…
PLEASE MAKE SURE IT ACTUALLY WORKS FOR AN EXTENDED PERIOD OF TIME BEFORE SENDING IT BACK
IT HAS BEEN SENT BACK TO ME TWICE IN THE LAST MONTH STILL NOT WORKING