Blacklisted for Prescribed Debt

I had my vehicle financed through WesBank from 2005 to 2010, when the vehicle was returned and sold on auction due to me not qualifying to re-finance the balloon payment. I app**** for a credit card through FNB in June 2020 but was declined because there was a balance outstanding after the vehicle was sold on auction. I phoned Wesbank and was told that the account has prescribed and that they cannot issue a paid up letter, nor can I pay the outstanding amount. They cannot even tell me for how long this will reflect on my profile, and even though my credit record with Transunion/Experian etc. is clean I will never qualify for any FNB/WesBank product other than a bank account. Surely after 10 years this should not still be an issue!!!