Standarbank overdraft

I would like to know how Standard Bank goes about this overdraft on a account.

I wasn't even aware of the overdraft until I saw my current account way in the minus.

I still had money available in on my available balance in my account. So how does this work, I have money available but then there is no money. How can I ever trust Standard bank to be certain I have enough money before spending.

I would have never spent any money if I knew I didn't have any but my current balance still said I have available.

This is ridiculous as I am now also paying honouring fees because of this. Once my salary gets paid in half of it will go to this overdraft I never asked for.

Can Standard Bank not just show the right amount available rather than catching on **** like this.

I am highly disappointed and will be moving banks soon.