The European Commission provides a platform for online dispute resolution (ODR): https://ec.europa.eu/consumers/odr.
You can find our e-mail address in the imprint.
We are not willing or obliged to participate in dispute resolution proceedings before a consumer arbitration board.
However, the law on alternative dispute resolution in consumer matters requires that we nevertheless point you to a consumer arbitration board that is responsible for you:
General Consumer Arbitration Board of the Centre for Arbitration e. V.
Strassburger Str. 8