HVAC problems

[2500hd owner]

2020 Chevy 2500hd HVAC problems.  1st issue was not heat on drivers side this past winter.  Took 2 month to get a good part to fix it.  GM sent 3 broken air box assemblies before dealership reviewed a good one.  Now the air conditioning is 12 degree warmer on drivers than the passengers side.  On low the drivers side is 62 degrees and passenger side is 50 degrees.  Dealership informed me the dash and seats would have to be removed for a 3rd to troubleshoot the issue.  Any one else have similar problems?  Contacted GM via email and there response was to contact the Better Business Burea.