If you quit, you have to talk to the store manager first, explain the reason for leaving, and theoretically, you'll be allowed to finish the shifts you've already scheduled.
Then you turn in your clothes, badge, employee handbook, whatever, and fill out a few forms.
There's nothing else you need to pay attention to. It's easy to leave a part-time job at KFC and no one will give you a hard time.
Also, there's no need to go to the extreme of using absenteeism for warnings, just talk to the store manager.
If you can't get on, just talk to the store manager directly, and be firm, and explain the reasons why you're there, and the management team will find someone to take over for you
.