FNB HOME LOANS DEPARTMENT incompetance

I have 2 properties bonded by FNB. they wanted to repossess my property due to outstanding payments. now when I have arranged the sale of the property. FNB cannot find the title deeds. and they want me to sign a document. under oath that THETITLE DEEDS are lost or destroyed, which is a false statement of declaration because I did not lose or destroy the documents. I may be wrong but as layman shouldn't FNB or a representative of FNB sign the declaration because they own the title deeds and they have lost it.as per my understanding the title deeds are actual proof of ownership so if FNB cannot produce the title deeds they cannot claim ownership if they need to request a copy why should I sign the application for as copy?