PAID UP LETTER STRUGGLE

I need a paid up letter that I have settled my loan. When I paid and send the POP on the 23rd October 2019 I was told a letter will be email to me within 3-5 days after endless emails and calls till today (11/11/2019) I don't have the letter. When I sent an email today to Sakhumzi whom I have been communicating with, he told me FNB has not responded who job is it to follow up with FNB is it mine. All you guys know is to harass people to pay but when they do you don't even deliver. I have an application for a house but cannot do anything cause I cannot get a paid up letter from you, the offer to purchase I signed for that house is expiring soon because of your incompetency to do your job, I will loose on the deal. I wont recommend anyone to pay their debt through you cause you just useless.