Arrears on inactive cheque account

I lost my job in March 2019 and received my final salary in April 2019. I had a cheque account with Nedbank. Obviously with no source of income, I did not use the account. Now I'm being harassed with messages threatening to attach my 'property' because apparently I owe R700 on an inactive account. Why not just close the account like normal banks? I would never go back to Nedbank even when I have a new job.