Outstanding Charges blocking account usage

I took out a transactional account with Discovery Bank when they launched in around 2019 as I had been with Discovery for over 10 years. I then kept the account but never used it because they were still new in the market and there were other functionalities I was still uncertain about so I did not switch fully to Bank. I called them a few days ago after getting a call from an agent wanting to offer me the same account, I called them to find out if I can resuscitate this account and give it a chance by switching my salary and day to day banking activities there to boost my vitality profile and to my surprise after not using this account for more than 2 years that I have an outstanding of R6000+ that I need to pay to Discovery before I can. I'm disappointed as a standing client of more than 10 years that an account that hasn't been used could owe that much, also what surprises me is that they were offering me the same account but when I resuscitate the account I'm told I can't use it till I pay R6000.