Overcharged fees that put my account in a minus

I am not happy with FNB’s services of lately. They over charged me when my account was in a minus to an amount of R1870 to my account when my account was in an access for 2/3 days. Normally I go and correct this as soon as I have time which I did and to my surprise on my way to the bank they charged me 120 7 times when they tried to debit my account for account fees and other charges. Normally they allow me a few days to correct my account when it’s in a minus but ever sinse they offered me an overdraft and I wasn’t willing to take it they implemented these occurring cost into my account. I’ve been banking with FNB for more than 12 years and this type of behavior I find very unsettling as it feels as if they *****ing from me to teach me a lesson. I don’t appreciate being over charged 7 (R120)times for them swiping for bank fees that they know is not there so that they can profit extra income from me. They don’t live up to their slogan as how can we help you rather to how can we ***** from you. I have reached the point of where I no longer want to be with this bank and researching other alternatives as it’s not the first instance that they have been of grave disappointment of late. I think this type of behavior is ********** and I want my money back that they took from me. Because what was supposed to be an excess of a low amount turned into an excess of a substancial amount which has now put me in debt. This is unfair and not make me trust this bank that is handling my money. I will pay up what I need to and close off this account as soon as I can. I’m tired of this bad service that I’m experiencing with a bank that doesn’t serve you and staff that show reluctance to assist when you go in and ask for assistance everything is always too much effort for them and they make you feel like you asking too much when you asking something simple