Disgruntled African Bank client

I'm an African Bank client, aged 55, full time employed in a managerial capacity at a blue-chip company and earn an above average salary. I recently app**** for an emergency loan and it was turned down. When I contacted customer service, I was told that my application was declined, due to an African Bank prescribed debt of more than 17 years ago. I neither could recall, nor had any information on the said debt. I then repeatedly tried to get information on the alleged debt from customer service consultants, but all they kept on telling me was "We can't see an amount or any other information on the debt" and I was then left in the cold. This is seriously affecting my relationship with the bank and I will take my business elsewhere. This leaves a bitter taste in my mouth and poor customer service at it's best!