FNB - shocking customer service.

I received an SMS this morning stating that a transactional hold has been placed on my account as there is a FICA document outstanding. I have not been contacted by FNB about this, by email, by phone or indeed through the app. I have spent the last hour on the phone, on hold constantly, then the agent answers and drops the call. I am trying to find the email address where I can send the required document. I am only guessing which document is required as I have been unable to get any information from FNB call centre.