SANLAM PERSONAL LOAN

I have requested a settlement letter which I settled the very same day .I received the settlement letter on the 31st March and settled the account on the very same day .When I wanted to close Loan account I was informed that there is an outstanding amount due to my Debit order that did not go off on the 28th .I have phoned the call center and get cut of about 5 times ,I have emailed the customer care center 3 times and have read receipts for the emails but still no one calls me back or answers my emails .I have logged a complaint on the website as well.