Chat feature not a pleasure to use

The banking app continues to frustrate me. I tried to switch off notifications but still receive pointless messages and beeps. I had the discomfort today of trying to communicate via the app chat, which I started through the computer online banking, but it continued on the phone app, only 30 minutes later, without any audible notification. So when I actually WANT a notification, I don't get one. The text is so small in those messages that I had to wear 2 pairs of glasses. Having done with my query, I then increased the font size for all programs on the android. Fonts in all other apps are larger, but the banking app font stays small. I have looked unsuccessfully for settings in the app. Have I missed something?