Useless FNB App

FNB forces you to make use of their app, I tried last night and again tonight to submit a query as I need assistance with 2 issues, however last night and tonight I get an error message when trying to submit a message through the app. How am I supposed to get any assistance? I am very busy and I don't have any time to waste. I need someone to contact me via my registered email address from your Wills department, and from from your Money Maximiser department. Do not phone me, I need to correspond by email.