paid up letter outstanding

i have settled my Nedbank credit card with Nedbank in November 2015 , i have phoned several times to request a paid up letter .And every time i was advise that my details was sent to the Department in Johannesburg and that they will issue me with a paid up letter . until today i have not receive any correspondence or any phone calls from Nedbank to confirm if i have received or if the letter is outstanding . This morning 23 December i phoned again to request the letter and was advise that the request was never sent to the relevant department to supply me with the letter ,and the staff member just inform me that he will refer the matter to the team leader to follow up . no action was taken to assist or try and resolve the query .