Money deducted after settlement of account

I have a Direct Axis loan and 2 weeks ago I transferred the balance amount to the loan account with the intention of settling it. I then called their call centre to inform them that I settled the account and the consultant that I spoke to reassured me that the account is closed and no deduction will be made this month. I was surprised when I found that the usual deduction was made on my cheque account. I then called them and informed them that a mistake had been made on their side but all I was told was that I will be called but no call has been made to me. I have been waiting for a while now and the consultant that I spoke to told me that they have many clients and I am not the only one. I already spent almost a hundred rand worth of airtime calling them but no solution has been reached.