Refuse to close my loan acc after settling

I have a personal loan which was in arrears, and I wanted to settle my personal loan account and therefore I called the collection department on the 16 April 2015 and was given a discount settlement figure of R17842.50, which was reduced by 20% of my full balance, and I was told that this settlement would be valid for 7 days... 4 Days later ( which was 20 April 15) African bank debited R1423 from my bank account and I paid the difference of R16419.50 via EFT which totalled R17842.50. When I called the call centre to confirm closure of my account and requested a paid up I was told that it would be done in 7 to 10 working day but till today I have not received or heard from your call centre. I made several calls to follow up and I spoke to the following agents in the interim