Disappointed by Nedbank

I have an account with nedbank under migoal plus and got assisted by an agent from nedbank because i wanted an overdraft. We went through the whole process of an overdraft application and he told me that I have been approved. He made me sign documents and told me to ask for the letter of appointment from my workplace of which I did but it's only now they send me an email saying that they can't approve my application because I'm not permanently employed. Like I'm angry because no one told me that from the beginning of the application process ,its only now they told me that I have to be permanently employed, I'm so angry right now because I had to bother my HR Manager to get that letter of appointment. For what exactly?