Very Amateurish
After using N26 for several months without complaint, they suddenly updated their app.  It was a mandatory update, and they disabled older versions.  This new update had the feature of a cryptographic signature requiring a direct download from the Google Play Store.  This is a problem for me because I don't agree with Google's terms and conditions or privacy policy.  I download my apps elsewhere.

Other banks use a cryptographic signature to verify the integrity of the app, not that I have agreed to Google's t&c.  This is like the old days when companies required you to have a Windows computer to use their services.

Anyway, this app upgrade abruptly made my account unusable and blocked most of my payment options.  It was days before I was able to get through to customer service on their chat window, and was obviously not the only one with a problem.  I asked them to close my account and transfer the balance, and they are unable to give me a time frame for completing this.