After you put in the alternator and battery, are you still have issues ? If not, then why go see the dealer ? If you are, it could be a parasitic load that is draining the battery. You may have to remove fuses one-by-one to figure out which electrical circuit has a problem.
It depends on your expertise and amount of spare cash you have to decide if a visit to the dealer is necessary. Electrical problems can be open-ended, and may cost more than the $200 that gets you in the door.
Good luck, and report back.
2018 Equinox LT1 1.5 L 4 cyl, AWD, S/R Cajun Red Tintcoat/Black
2010 Equinox LTZ 2.4 L 4 cyl, FWD, S/R Cardinal Red/Black