Terrible service from Nedbank

I app**** for a credit card after I have been receiving offers to a apply for either a gold or platinum credit card from Nedbank.I did this also to increase my credit score even more to ensure that future home loan applications will be a success. I did an online application which pre-approved me for an amount of up to R80000.00 which I then sent a copy of my ID for. After having to call with my own airtime to follow up if the ID had been received I spent another 20 mins on the phone redoing the complete application. Only to be declined this earlier today. When I called to enquire why they said its because I have an account at legal! I mean I have no knowledge of an account at legal? If someone can please explain to me what is going on???! I had a Nedbank bank account many many years ago I think it could be at least 6-7 years ago. If I had owed them anything should the legal department not have contacted me? I have not seen anything from Nedbank ever on my credit report? My details gets updated regularly at the credit bureau so should I have owed them anything whtu has no one ever contact me or sent mail via the post? Should have debt not been prescribed after 3 years should the be a balance? I cannot appeal an application and reapply as enquiries messes up my credit score. Can someone from Nedbank please sort this out or contact me? This is really bad for a bank who people expect more from.