2001 Hyundai Trajet Hyundai starting issues

Recently I bought a hyundai trajet and it had a intermittent problem where you had to keep turn the ignition keys several times before the engine would turn over and start now its a big problem as it wobt fire up at all or turn over I get all the ignition lights on immobiliser blinks six times abd goes out but the engine will not turn over it will push start though the garage said it was the starting motor so I fitted a working second hand one and a new battery to and the car still is exactly the same none of the garages know what the problem is I've tested how much power is getting to the starting motor and its only 0.9 volts at the starter fuse there is approx 12volts everything in the car works but the engine just wont turn over