The Broken AC Fallacy?

###posting on behalf of an anonymous user###

Several years ago I purchased a new Volvo.
From the outset the air conditioning would intermittently stop blowing cold air.
There was no pattern or identifiable precipitating cause.
The intervals between incidents were unpredictable; the duration was inconsistently consistent.
Each time I scheduled an appointment for a mechanical evaluation, the AC worked perfectly.
The Volvo dealer repeatedly concluded that the AC was working fine.
I assume they thought I was a kook.
After 6 nonproductive visits I decided that when the AC acted up if I was close to the dealership I would bring it in immediately to have the problem documented.
Finally I was able to have a mechanic witness the AC blowing tepid air.
Eventually it was determined that it was a bug in the computer software,not a mechanical issue.
Were the mechanics at the dealership committing a logical fallacy in denying that the AC was defective?
Under what category of logical fallacy would this fall?

When I was about four years old and living in a small town in Connecticut, I told my parents that there was a monkey in our backyard. They clearly did not believe me and thought I was just using my imagination as I have been known to do at that age. That evening, they saw on the news that a monkey escaped from the local zoo. Although I was right and my parents were wrong, they were fully justified in coming to the conclusion they did.

Does a team of qualified technicians looking for problems and not finding any warrant a reasonable conclusion that no problem exists? Perhaps, but if it was a software problem, one would expect the dealership as a whole to be aware of the possible issues before concluding that "no problem exists" (at the very least they could have said that they "could not find any problems"). Overall, I would classify this under Argument from Ignorance : "Because we are ignorant of any problems then we conclude that no problems exist."