If these issues are intermittent and do not occur when the dealer has the vehicle, then it's tough to make them happen when they are looking for the problems. Personally, I have little time for these type of problems, so I understand your frustrations. I have been lucky with my last several vehicles in that they either had no issues or minor ones that were easily corrected. BTW, the last six (seven including the wife's Malibu) cars were all GM products.
In the past, if I have taken a vehicle to a dealer a number of times and the issues went unresolved, I would try another dealer, hopefully with better technicians and customer service. Maybe a Chevy dealer can help as they sell the same vehicle (an Equinox). Of course all your service visits are available for every GM dealer on their computer. Here is the part you may not like, after the problem(s) were not fixed, I have just traded the vehicle in for another vehicle. Yes, it's a costly solution, but it usually works. When the Acura dealer was about to install the fourth transmission into my 1998 Acura (my last Japanese car), I traded in for a 2003 Chevy Blazer.
Whatever you decide to do, I hope someone can solve the issues.