Screen wont turn on after 3-4days

Question

I AM RETURNING 4TH TOM TOM IN 3WEEKS BACK TO WALL MART .UNIT WORKS GREAT BUT AFTER 3-4 DAYS SCREEN WONT TURN ON . I LEAVE IN TURNED OFF WHEN NOT IN USE BUT PLUGGED INTO TO CIG LIGHTER IN CAR. LAY ON FLOOR WITH TOWEL OVER IT SO NO ONE WILL SEE IT. I CANT BELIVE I GOT 4 BADS ONE IN A ROW.