Terrible from FNB

Shocked at the service from FNB. I am trying to secure a home loan with my bank that I have banked with for over 20years. They came up with an excuse that I need to confirm settlement of a revolving credit, I have not used this facility in months and I settled long time ago. I have been holding the phone for 40minutes for a consultant and still no help. I owe FNB zero and why do I need to prove that I don't owe anything. Can they not speak to each other and this is really ridiculous. The guys at the tellers told me only the people on the phone can confirm that I have settled the account. Do I need to go through this with my bank. Or should i take my business elsewhere.