No paid up letter for paid up account. FNB keeps me hostage from being cleared of debt review..

I am very frustrated and dissapointed with FNB. I have been banking with them my whole life. I have put myself under Debt Review a year ago, and managed to pay off all my debt. Now I needed to get paid up letters to give to my debt review company and that was easy enough. But it seems an impossible task with FNB. I sent mails to all the correct departments at FNB. I had the matter escalated numerous times also, but I am still waiting for a paid up letter for debt I paid up almost 4 months ago. Yes, I am tyrying to get the paid up letter from FNB now for almost 4 months. I even involved my banker who have sent numerous escalations on my behalf also. I have to ask for feedback every week. He has sent it to so many managers now that the whole FNB must have seen these escalations. But still no paid up letter. What must one do to get FNB to do a basic task like a paid up letter? I am unable to go on with life because FNB decided to keep me hostage by not giving me my paid up letter. But FNB want to sell me life insurance and all their products as I have no debt. So they can sell me their products, but now I doubt they are capable as FNB cant even type out a simple paid up letter. All I need to get out of debt review is this letter and FNB fails to provide it?