CANT FIX THE CAR

Barons vw took in my car Golf 5 3weeks back it had a problem of cutting it self while it running. And It dont show warning lights on the dash. I towed it to VW Barons in pmb they booked for it and they couldnt fix it, when I check up on them they say they need more time. So they said they will rebook for the car but it was with them.