Terrible Customer Service - Frustrated and Angry Customer

I am a premier banking customer and have been for the past 2 years, after switching from Absa. In order to increase my ebucks reward level I app**** for an overdraft facility using the FNB banking app. My application was declined for credit reasons. I have no accounts and no debt. Naturally this sent me into a panic and I thought I could simply call into FNB and request information relating to the reason for the decline. Well 3 customer agents later, over R100 in airtime, numerous dropped calls, failed transfers I still do not have a reason relating to this decline. I have contacted transunion as advised and they have told me my credit rating is absolutely fine. It is not acceptable for any company to decline credit and not provide you with a clear reasoning. I should mention that I was granted a R29 000 loan over the phone, wihout me applying for it, without a change in circumstances. If I do not get a call back shortly I will have no choice but to revert to reporting them to the Credit Ombud