Engen 1App

Using engen 1App brought me in distress. I had money into the app and went to fill up the car. As I was about to pay the app had no funds😳. In this December really?! I called their call centre and was on the line for more than 6 minutes without help and eventually resorted to them calling me back. This was an embarrassing moment, had to call someone to come and pay for my bill while I thought my funds are safe in the App. I'm still waiting for answers. This app is not convenient at all!!!!