********** debit after settling my debt with nedbank

I had a shortfall of which I had to pay R22000 as they had financed my vw polo in 2013 which got involved in an accident so i agreed to pay R450/month which I obliged to. When I request a statement I get taken from post to pillar,until recently was assist by a lady who informed and confirmed my suspicion that the account had been settled but by far they owe me and my calculations it's an amount of R5000 owed to me. She then transfered my calls to their accounts where I got ignored and my call was dropped off. I called again and was promised to be called Friday the 27 which is today... No one had contacted on why my account had been debited even after my shortfall had been settled long ago