I have a 2017 hyundai sonata hybrid with only 50 thousand miles on it, bought it used but its in really good shape but recently i took it to the dealership to get a full service, they changed the oil and it's filter, they changed the transmission oil, the fuel filter and the air filter as well as the spark plugs. when i went to take the car back and after driving it i noticed an incredibly low gas mileage and a noisy engine, the engine also shakes sometimes at idle and the shaking won't stop until i give it some gas, took it back to them so that they can find out whats wrong and they say everything is fine each time, right now it's only getting 26 MPG when the engine is running and its running a lot noisier than it should be and it also makes a really weird ticking noise at high RPM/ acceleration. there are no check engine lights and no loss of power just bad fuel economy+ noisy engine.