I'm going to go classic and name a company that personally wronged me: Noodles & Co. I used to work in a mall and every single restaurant in the mall had a mall employee discount. It was usually a token discount between 5-10% but still it made a difference on your lunch break during an 8 hour shift. Noodles & Co. had no discounts for mall employees and one time I found a hair in my food there. It's petty but since then I have never returned to that restaurant
Goya. It's easy to forget amidst the tsunami of far more severe bullshit between 2016 and 2020, but then Trump abused his authority to hawk a fucking bean advertisement in the oval office instead of leading the country during a pandemic... yeah, decided I'd never buy a Goya product again, ever.