Terrible service, doesn't care about their client

I have to go through the same thing every month. A bank I have a loan with went into my account and debited unauthorized amount and debited twice even and took all my salary of my account, I have not paid my other bills which are now going to return thanks to the unauthorized debit order I have not food, transport money, rent money. They refuse to reverse my money and FNB also refuses to assist me with reversal dispute being their customer. I don't know how I need to go by June when my bank doesn't even want to assist me.