BMWM6 Faulty engine. BMSA fail to honour warranty obligation

BMWSA fails to honour their obligations. In October 2017 I purchased a BMW M6 at Bedfordview BMW. For the past six months the car has been at the dealership due drivetrain malfunctions instead of replacing the engine as it is their warranty obligations, they keep on looking for solutions and the car keeps on going back to the dealership with same problem. BMSA fails to honour their obligations under warranty to replace the faulty engine.