It can be really difficult to deal with any support organization of any product.
If you did not INSIST the First Responder [NOT trained to read panic reports] escalate your issue to additional Specialists to read your panic reports and determine the cause, or insist they file a Formal Bug Report on your behalf for a software issue, you have now determined experimentally:
Just how much time can be spent working with Apple Support without getting REAL resolution of your issue.
If you do NOT have panic reports, your best bet BY FAR is to start a discussion right here and ask other users for things to consider. No one anywhere is going to wade into your logs looking for a solution to a problem that happens sporadically without an immediate way to reproduce the problem.
ONLY If you have enough evidence to proceed, in panic reports or reproducible on demand symptoms, consider calling them back, noting all your previous work toward a solution (which they can look up), including your unproductive Genius Bar visit. Be polite and professional, but keep your eyes on what needs to be accomplished. You may need to be a little more assertive on your own behalf.
If your problem is not solved, do not release the person you are dealing with unless/until they give you an escalation/referral, or tangible plan for actual resolution.
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Genius Bar:
When you present your computer at the Genius Bar with the expectation of a quote to repair it, you must generally meet these criteria:
• your Mac won't do anything
• your Mac fails diagnostics
• your Mac has a problem you can repeatably demonstrate on demand
one other oddball case:
• Apple online support has DIRECTED a Service Provider to replace specific components inside your Mac, such as the mainboard or display. Bring proof, such as case number.
They CAN run their diagnostics, which are a bit more comprehensive that the User diagnostics. In the very small amount of time they are run, “No faults detected” still does not mean “All is Well” but at least there are no detected GROSS problems.
ANY other visit to the genius bar can be an exercise in futility, because technicians are not trained to read panic reports. If your issue is only illustrated in panic reports, you need an Apple Support Specialist to read your reports, determine what is causing the Hardware problem, and DIRECT a Service Provider what they should change.
EDITed for clarity, be sure to re-read.