Suzuki Hatfield extremely bad service

The worst service possible. When I called to make a booking for my car's service they quoted me almost double than what other dealerships quoted me and only adjusted the price when I questioned the price. Then they wanted to charge me for replacing the spark plugs, which they were supposed to replace with the previous service while the car was still on its service plan. When I got the car back it was not washed at all. Since I got it back the car has n strong smell of clutch which it never had before, when I called them to complain the manager denied that they had touched the clutch and that they only tested it. They also claim that they adjusted the hand brake during the service, but since I got the car back the handbrake does not work and can't keep the car stationary on a incline.