Dollar General

Two days ago I was given my write up for a ncns. It wasn't intentional, I had my teeth out and was on medication. I completely slept through my shift... Well, a few week leading up to my ncns, another employee had ncns... No write up! And I verified with said employee before filing this.. Why am I the only one being wrote up for this and no one else is?! You can't be unfair like that..