Frustrating FNB approach

FNB is trying to FICA my trust details in a very unprofessional way. I received an email with the contact details, of which some was outdated. I corrected the incorrect information and signed the document. I also attached documentation to support the changed information. Despite doing this, FNB keeps sending me the same same email with the incorrect information. I received a few calls from FNB, however, the phone rings once and then stop. When I call back, I end up in a long queue at a call center. This is really disappointing. It is not the kind of behavior of an organisation that want to retain customers and gain more.