Hate my job , need to vent

So yesterday before I started my double I was told my relief will be an hour late , which I didn’t mind because my appointment wasn’t tell 10:15am. So I start me 3pm-8am shift . 9:00am rolls around no one . So I waiting tel 9:15 ( just because I know how traffic is at here) . Call my job to let them know that no one is here . Come to find out she wasn’t never coming tell 11am . So my question is why the fuck would you tell me 9am if it really wasn’t tell 11am ?. I wouldn’t be so mad but I’m pissed the fuck off for the simply fact that I could had rescheduled my appointment for later on today . And let’s not forget this girl is ALWAYS late . 36 weeks and stressing over this job, and their liessss🤬🤬🤬