****ed off client

I’m really unhappy and I feel like all your staff need training. I had four uncleared transactions for R749, R93, R46 and R215 these transactions exceeded my current balance. I called and the lady told me that the uncleared transactions would come off my available balance I went into the bryanston branch and was told the available balance is my money to use so I purchased airtime . I wake up the next day and my available balance is now zero and my current balance is in the minus . I don’t have or don’t want an overdraft I want to understand why my current balance is in the negative