An apparently opaque and unresponsive non-service
I have good credit, no arrests (e.g.), but when I applied for a free N26 account so that a colleague outside the US could send me some money without paying a large transfer fee, I was denied. I spent time on the phone with customer service trying to find out why, and I was told nothing. N26 refused to provide any information whatsoever.

This policy should change immediately: people who spend time applying to use a service (that is, would-be customers) deserve some minimal explanation of why that service would refuse to work with them. This explanation could even be built into the application to save both parties time, and to preserve the reputation of the service as customer-oriented.