I cannot understand this "no fault code" = "no
problem" mentality. The OBD was primarily designed to detect emissions problems to ensure compliance with legislation. As a bonus, having computers all over the car means you can detect other problems also, such as climate control, locking etc. BUT it doesn't mean the computer can detect every thing that is wrong with the car!
Mechanics, sorry "technicians" should still be "diagnosticians".
Imagine if this mentality was extended... you walk into casualty with an arm hanging off with a spurting arterial bleed - "oh sorry, the intelliscan says you're fit and healthy maybe come back in a few weeks and see if it says anything then"
I'm not sure if it's just poor training or some manufacturer mandate to cut the cost of warranty claims, but they just won't look at problems like they would in the "good old days".
If your car is less than 6 months old REJECT IT NOW as you are entitled to if they won't repair it.