If it was listed on your work order to repair the RIGHT side but they did the LEFT side they should do the side that was listed for free. You may have to fight them for it, service mgr, GM all the way up to the owner. Don't know if a lawyer would be worth it.
2018 FWD Terrain Denali, Steel Blue Metallic, 2.0L Turbo, Sunroof.
2017 FWD Acadia Denali, Crimson Red Tri-Coat, V6
2014 FWD Buick Enclave Leather
2012 FWD Equinox 2LT V-6,