Useless bank

I'm so disappointed in nedbank so I just opened an account with them first of all I was told my charges would be R5 a month then all of a sudden they deducted R35 when I enquired I was told it was greenbucks ok so that was settled. On Friday 23 of November it was my birthday and I received money and only used it during the weekend ok so my problem now is I have a negative balance of R227 and when I call the call center they are telling me that I had pending transaction and while I was shopping I exceeded my available balance. I explained to the lady that I was checking my balance while buying and she said they are the only ones that can see the pending transactions, what nonsense is that so I must calculate for myself while I have a banking app and sms notification which I get charged for when I asked her this question they dropped the call on me so now I owe the bank money for their faulty system. What irritated me the most was that I was told that I should have known how much I had in my account while the available balance was favorable the whole time. How was I suppose to know they are pending transaction if they are the only ones that can see them.