Car went for repairs from March to date

I bought a brand new car, model FAW SERIUS at the Kia the Glen multi-franchise garage in June 2013.The car showed an engine light few months after buying it.The problem was reported to the garage and the car has been booked in the garage several times but the light never went off.In March 2015 the car was booked in again and they decided to dismantle the engine to fix the problem. The car has been at the garage since March 2015 to date.The garage alleges that they are waiting for the parts of the car.The car is lying there and there is no indication that the car is being attended to.I am paying monthly installments for the car lying at the garage.Every time I go check the car Eugene tell me stories.On 26 September 2015 I went to check how far are they and they told me the same story that they are waiting for the parts.I then requested that they should provide me with temporary vehicle as I can see that they are not showing any sense of urgency.I am frustrated please help.