The EU Commission offers the possibility of online dispute resolution on a platform operated by it (so-called “ODR platform”). The ODR platform can serve as a point of contact for the out-of-court settlement of disputes arising from online sales contracts or service contracts. This platform can be accessed via the external link https://ec.europa.eu/consumers/odr/main/index.cfm?event=main.home2.show&lng=DE.
You can also send any complaints to the e-mail address given above.