You can make a complaint by contacting us or through the 'Complaints' section of your account with any information you believe is relevant.
If you are unhappy with the service offered by one of the companies offering a value added service on Onsi, then you should reach out to them directly to complain.
If you are having a technical issue with our website or app, then please let us know through this link or this email support@zurich.onsi.com