"It cannot be that financial institutions are doing well because they treat their customers badly," Chan-Jae Yoo, a BaFin official, said in an interview.
Deutsche Kreditwirtschaft, an umbrella organisation that lobbies for German finance, said German banks are "extremely stable and robust" and confidence remains "high" and "unaffected" by recent turmoil stemming from the collapse of lenders in the United States and Switzerland.
"The mere fact that consumers are increasingly asking us and seeking our advice is proof enough that they do not fully trust financial institutions," he said.
Protections and rights for customers of financial institutions have come under increased scrutiny from regulators and the German courts.
"We want services to establish themselves in the marketplace that meet consumer needs, not feed the financial industry," he said.