Shocking Customer Service!!!!

Shocking customer service. I have been requesting a paid up letter for an account that was settled on 30 September. Its now 24 October and nothing. I have sent numerous emails and called the call centre numerous times. Empty promises to "escalate" my query with absolutely nothing happening. They listed me on the credit bereau from April this year, stating I was a late payer - which is absolute nonsense. I have proof of all my payments. Decided to settle the account so that I can apply for a home loan, but I cannot get home loan approval without that paid up letter. Call centre calls get dropped. call centre agents put you on hold for 10 min and then drop the call and they tell me they cannot make outside calls to get back to me. FNB - you so quick to take our money, but when we need a paid up letter - this is the type of service you give us??? Thank goodness my main banking is with Nedbank.