CHeque Account Closed in 2012

I closed my cheque account in 2012 and returned the card to the branch. Now I am being told that I have an outstanding amount of R700 that I need to pay to avoid my name being blacklisted. The last activity on the card and account was 2012 as it is visible on their computers. So why should I pay for thei own mistakes? And why only now in 2015 they took my name to the collectors? They can track back the calls I made to the call centre since our calls are being recorded, I can't be expected which consultant I spoke to in 2012 and the staff member.