Cannot buy Data on FNB app

Fnb app not working, for the last few months now its a struggle to use the fnb app, when ever i try to buy data, vodacom, i get a “system currently unavailable” message, it really is frustrating! Fnb advertise that you can buy Data anytime anywhere! I need the data urgently!!! Fnb please get your app like its was! Get it to work properly again! The number on the error screen cannot help you ***, tried them, very poor connection and no help, you have to call at 8 in the morning, guys the app support is supposed to be 24h if not, please advertise that your app is only functional between 8 and 5