Barons VW woodmead service(Poor Service)

Yesterday I took in my car for service at VW Woodmead. The problem started when I collected the car ,once I was driving on the free way the EPC light came on and when I press the accelerator pedal a sound came from the engine compartment and I then took the car in this morning, I was told some pipes in the engine were not connected properly and it was pulling air in instead of fuel.

They then sorted problem with the car, but my question is how do u give a customer the car without testing it, were quality checks done , what if something could have happened while I was driving on the free way. I'm really disappointed with VW Barons Woodmead.