FNB money missing and overdrafts while having enough money

FNB is not the bank you wanna bank with. For the second time now that I wake up with money deducted on my account and them saying that it is due to an overdraft. While there was money in my account, so how? How does this happen. Today I am fed up because you keep taking money from our pockets that we have plans with. I am left stranded because of the stupid bank. Last time I just end up going to the bank and still no solution, today again I spent so much airtime calling them to get to understand the issue. I want my money bank!! This is ridiculous! They are telling me my account went into an overdraft because it was running negative! How was it running negative! I want my money back. You can’t prove this on the app. We just keep calculating back and forth back and forth. I’d like to advise all of you to stay away from this bank. My friends experienced this too several times and they made that decision to change, but I stayed hoping it wouldn’t reoccur, but here I am and my money is gone!