Worst service and dishonest

Worst service and most dishonest about vehicle inspections. A Car went in to check fuel gauge not working and vibration/ shudder when driving at slow speed Came back and Audi representative Jolandi said no fault found and fuel gauge had nothing wrong with it When driving the vehicle the shudder was 10 times worse - went back in and was told nothing wrong and after insisting they look further suddenly found a shudder and fault with petrol gauge - when I asked the rep why it wasn’t picked up she said it all depends on who tests it. In conclusion you cannot trust the report when you get your vehicle back because it all depends on who tests your car, lol My car is still not fixed and it’s under motor plan