FNB Does not want to give me paid up letter after settling the account

I have been trying on several times to get FNB to send me the settlement letter and update the information with the credit berux without any success,i have requested a settlement letter from FNB of wich i have paid the amount due and send the proof of payment ,i have called them and even visisted the branch in carswald and sandton they keep on sending me from pillar to post ,i need the settlement letter and account updated with transunion