Help!! U80V - 3D gaming problem

hi everyone i need some help ...

i just bought my u80v last 2 months ago but it had been sent in to repair for 3 times and eveytime i sent in need ard 1 week to take back my lappy .. But the problem still there ..

My lappy problem is when i play 3D games (dragonica,cabal,fiesta) for ard 30mins, sometime even play for 10mins it will auto restart. The first time they said they check everything n is totally fine n tried on some games like maple n audition then when they return they even guarantee that it wont happen again but still disappointed me.
I sent the 2nd time then after a week they told me is game patches problem after i collected my lappy i tried for 1hr playing 3D game it seems ok but not until there are new patches for the game then after the new patch it happens again auto restart.
Then i sent in the 3rd time ... They keep telling me the same thing which i cant really satisfy n im not really noe abt it & computers. Now waiting for them to test again n let me noe how is it going.

Is anyone having the same problem with me? Anyone can help...

This is the first time i buy asus n also will be my last time n the support team of asus is disappointed me is not supporting at all.
My friend help me to updates all my graphic n even bios n also wont works