In all likelihood the only route you have to deal with fraudulent activity is through your bank/card provider.

You can contact Eurail customer services here https://eurail.zendesk.com/hc/en-001/requests/new

But it is unlikely they will be able to do anything for you, you need to deal with unauthorized activity with AMEX.

Thanks. Yes, I was led to the same and sent a note through the Zendesk. We shall see.  Probably speaks volumes that they don’t even have a phone #.