poor HR response, unfair firing - After School Instructor Safe Passages Employee Review

HR is run by one person and if she isn't there, you will not get a response after an incident. i was fired for a minor infraction after no formal warnings or reprimands and had to wait five days to learn the status of my job and what i had done wrong. finally after a 7 minute zoom call i was fired and given no chance to defend myself or explain what happened. they took one person's testimony and got rid of me.